Merge branch 'next'

62 files changed, 6617 insertions, 920 deletions

diff --git a/host/docs/CMakeLists.txt b/host/docs/CMakeLists.txt
index 5926e062e..88afb9c98 100644
--- a/host/docs/CMakeLists.txt
+++ b/host/docs/CMakeLists.txt
@@ -30,6 +30,7 @@ SET(manual_sources
     transport.rst
     usrp1.rst
     usrp2.rst
+    usrp_b1xx.rst
     usrp_e1xx.rst
 )
 
diff --git a/host/docs/general.rst b/host/docs/general.rst
index ff85fb0f9..cc00fc0f9 100644
--- a/host/docs/general.rst
+++ b/host/docs/general.rst
@@ -61,6 +61,42 @@ Pseudo-code for dealing with settling time after tuning on receive:
     usrp->issue_stream_command(...);
 
 ------------------------------------------------------------------------
+Overflow/Underflow notes
+------------------------------------------------------------------------
+**Note:** The following overflow/underflow notes do not apply to USRP1,
+which does not support the advanced features available in newer products.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Overflow notes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+When receiving, the device produces samples at a constant rate.
+Overflows occurs when the host does not consume data fast enough.
+When UHD detects the overflow, it prints an "O" to stdout,
+and pushes an inline message packet into the receive stream.
+
+**Network-based devices**:
+The host does not back-pressure the receive stream.
+When the kernel's socket buffer becomes full, it will drop subsequent packets.
+UHD detects the overflow as a discontinuity in the packet's sequence numbers,
+and muxes an inline message packet into the receive stream.
+
+**Other devices**:
+The host back-pressures the receive stream.
+Therefore, overflows always occur in the device itself.
+When the device's internal buffers become full, streaming is shutoff,
+and an inline message packet is sent to the host.
+If the device was in continuous streaming mode,
+the UHD will automatically restart streaming.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Underflow notes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+When transmitting, the device consumes samples at a constant rate.
+Underflow occurs when the host does not produce data fast enough.
+When the UHD detects underflow, it prints an "U" to stdout,
+and pushes a message packet into the async message stream.
+
+------------------------------------------------------------------------
 Threading notes
 ------------------------------------------------------------------------
 
@@ -114,3 +150,21 @@ For a module to be loaded at runtime, it must be:
 * found in the UHD_MODULE_PATH environment variable,
 * installed into the <install-path>/share/uhd/modules directory,
 * or installed into /usr/share/uhd/modules directory (unix only).
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Disabling or redirecting prints to stdout
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The user can disable the UHD library from printing directly to stdout by registering a custom message handler.
+The handler will intercept all messages, which can be dropped or redirected.
+Only one handler can be registered at a time.
+Make "register_handler" your first call into UHD:
+
+::
+
+    #include <uhd/utils/msg.hpp>
+
+    void my_handler(uhd::msg::type_t type, const std::string &msg){
+        //handle the message...
+    }
+
+    uhd::msg::register_handler(&my_handler);
diff --git a/host/docs/index.rst b/host/docs/index.rst
index 40fe64599..b4ebdad6c 100644
--- a/host/docs/index.rst
+++ b/host/docs/index.rst
@@ -24,6 +24,7 @@ Application Notes
 * `USRP1 Application Notes <./usrp1.html>`_
 * `USRP2 Application Notes <./usrp2.html>`_
 * `USRP-N2XX Series Application Notes <./usrp2.html>`_
+* `USRP-B1XX Series Application Notes <./usrp_b1xx.html>`_
 * `USRP-E1XX Series Application Notes <./usrp_e1xx.html>`_
 * `Daughterboard Application Notes <./dboards.html>`_
 * `Transport Application Notes <./transport.html>`_
diff --git a/host/docs/usrp_b1xx.rst b/host/docs/usrp_b1xx.rst
new file mode 100644
index 000000000..2f7385070
--- /dev/null
+++ b/host/docs/usrp_b1xx.rst
@@ -0,0 +1,76 @@
+========================================================================
+UHD - USRP-B1XX Series Application Notes
+========================================================================
+
+.. contents:: Table of Contents
+
+------------------------------------------------------------------------
+Specify a non-standard image
+------------------------------------------------------------------------
+The UHD will automatically select the USRP B-Series images from the installed images package.
+The image selection can be overridden with the "fpga" and "fw" device address parameters.
+
+Example device address string representations to specify non-standard images:
+
+::
+
+    fpga=usrp_b100_fpga_firmware.bin
+
+    -- OR --
+
+    fw=usrp_b100_fw_firmware.ihx
+
+------------------------------------------------------------------------
+Changing the master clock rate
+------------------------------------------------------------------------
+The master clock rate of the USRP embedded feeds both the FPGA DSP and the codec chip.
+Hundreds of rates between 32MHz and 64MHz are available.
+A few notable rates are:
+
+* 64MHz - maximum rate of the codec chip
+* 61.44MHz - good for UMTS/WCDMA applications
+* 52Mhz - good for GSM applications
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Set 61.44MHz - uses external VCXO
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+To use the 61.44MHz clock rate, the USRP embedded will require two jumpers to be moved.
+
+* J16 is a two pin header, remove the jumper (or leave it on pin1 only)
+* J15 is a three pin header, move the jumper to (pin1, pin2)
+
+**Note:** See instructions below to communicate the desired clock rate into the UHD.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Set other rates - uses internal VCO
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+To use other clock rates, the jumpers will need to be in the default position.
+
+* J16 is a two pin header, move the jumper to (pin1, pin2)
+* J15 is a three pin header, move the jumper to (pin2, pin3)
+
+To communicate the desired clock rate into the UHD,
+specify the a special device address argument,
+where the key is "master_clock_rate" and the value is a rate in Hz.
+Example:
+::
+
+    uhd_usrp_probe --args="master_clock_rate=52e6"
+
+------------------------------------------------------------------------
+OS specific notes
+------------------------------------------------------------------------
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Linux - setup udev
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+On Linux, udev handles USB plug and unplug events.
+The following commands create a udev rule for the B100
+so that non-root users may access the device:
+
+::
+
+    echo 'ACTION=="add", BUS=="usb", SYSFS{idVendor}=="2500", SYSFS{idProduct}=="0001", MODE:="0666"' > tmpfile
+    sudo chown root.root tmpfile
+    sudo mv tmpfile /etc/udev/rules.d/10-usrp_b100.rules
+    sudo udevadm control --reload-rules
diff --git a/host/include/uhd/convert.hpp b/host/include/uhd/convert.hpp
index 8fc2f38db..99f1860ae 100644
--- a/host/include/uhd/convert.hpp
+++ b/host/include/uhd/convert.hpp
@@ -29,7 +29,7 @@ namespace uhd{ namespace convert{
 
     typedef uhd::ref_vector<void *> output_type;
     typedef uhd::ref_vector<const void *> input_type;
-    typedef boost::function<void(const input_type&, const output_type&, size_t)> function_type;
+    typedef boost::function<void(const input_type&, const output_type&, size_t, double)> function_type;
 
     /*!
      * Describe the priority of a converter function.
diff --git a/host/include/uhd/transport/usb_zero_copy.hpp b/host/include/uhd/transport/usb_zero_copy.hpp
index b39171fba..dc344ad8b 100644
--- a/host/include/uhd/transport/usb_zero_copy.hpp
+++ b/host/include/uhd/transport/usb_zero_copy.hpp
@@ -1,5 +1,5 @@
 //
-// Copyright 2010 Ettus Research LLC
+// Copyright 2010-2011 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -49,6 +49,7 @@ public:
      * \param recv_endpoint an integer specifiying an IN endpoint number
      * \param send_endpoint an integer specifiying an OUT endpoint number
      * \param hints optional parameters to pass to the underlying transport
+     * \return a new zero copy usb object
      */
     static sptr make(
         usb_device_handle::sptr handle,
@@ -56,6 +57,24 @@ public:
         size_t send_endpoint,
         const device_addr_t &hints = device_addr_t()
     );
+
+    /*!
+     * Make a wrapper around a zero copy implementation.
+     * The wrapper performs the following functions:
+     * - Pad commits to the frame boundary
+     * - Extract multiple packets on recv
+     *
+     * When enable multiple receive packets is set to true,
+     * the implementation inspects the vita length on transfers,
+     * and may split a single transfer into multiple managed buffers.
+     *
+     * \param usb_zc a usb zero copy interface object
+     * \param usb_frame_boundary bytes per frame
+     * \return a new zero copy wrapper object
+     */
+    static sptr make_wrapper(
+        sptr usb_zc, size_t usb_frame_boundary = 512
+    );
 };
 
 }} //namespace
diff --git a/host/lib/convert/CMakeLists.txt b/host/lib/convert/CMakeLists.txt
index d189aa687..5f05b0cb8 100644
--- a/host/lib/convert/CMakeLists.txt
+++ b/host/lib/convert/CMakeLists.txt
@@ -26,6 +26,7 @@ MESSAGE(STATUS "")
 ########################################################################
 IF(CMAKE_COMPILER_IS_GNUCXX)
     SET(EMMINTRIN_FLAGS -msse2)
+    SET(NEON_FLAGS "-mfloat-abi=softfp -mfpu=neon")
 ELSEIF(MSVC)
     SET(EMMINTRIN_FLAGS /arch:SSE2)
 ENDIF()
@@ -47,12 +48,53 @@ ENDIF(HAVE_EMMINTRIN_H)
 ########################################################################
 # Check for NEON SIMD headers
 ########################################################################
+SET(CMAKE_REQUIRED_FLAGS ${NEON_FLAGS})
 CHECK_INCLUDE_FILE_CXX(arm_neon.h HAVE_ARM_NEON_H)
-IF(HAVE_ARM_NEON_H)
+UNSET(CMAKE_REQUIRED_FLAGS)
+if(HAVE_ARM_NEON_H)
+    MESSAGE(STATUS "Enabling NEON support")
+    SET_SOURCE_FILES_PROPERTIES(
+        ${CMAKE_CURRENT_SOURCE_DIR}/convert_with_neon.cpp
+        PROPERTIES COMPILE_FLAGS "${NEON_FLAGS}"
+    )
     LIBUHD_APPEND_SOURCES(
         ${CMAKE_CURRENT_SOURCE_DIR}/convert_with_neon.cpp
     )
-ENDIF(HAVE_ARM_NEON_H)
+else(HAVE_ARM_NEON_H)
+    MESSAGE(STATUS "Disabling NEON support")
+endif(HAVE_ARM_NEON_H)
+########################################################################
+# Look for Orc support
+########################################################################
+FIND_PACKAGE(PkgConfig)
+IF(PKG_CONFIG_FOUND)
+PKG_CHECK_MODULES(ORC "orc-0.4")
+ENDIF(PKG_CONFIG_FOUND)
+
+FIND_PROGRAM(ORCC_EXECUTABLE orcc)
+
+IF(ORC_FOUND AND ORCC_EXECUTABLE)
+    INCLUDE_DIRECTORIES(${ORC_INCLUDE_DIRS})
+    LINK_DIRECTORIES(${ORC_LIBRARY_DIRS})
+    ENABLE_LANGUAGE(C)
+
+    SET(orcc_src ${CMAKE_CURRENT_SOURCE_DIR}/convert_orc.orc)
+
+    GET_FILENAME_COMPONENT(orc_file_name_we ${orcc_src} NAME_WE)
+    SET(orcc_gen ${CMAKE_CURRENT_BINARY_DIR}/${orc_file_name_we}.c)
+    MESSAGE(STATUS "Orc found, enabling Orc support")
+    ADD_CUSTOM_COMMAND(
+        COMMAND ${ORCC_EXECUTABLE} --implementation -o ${orcc_gen} ${orcc_src}
+        DEPENDS ${orcc_src} OUTPUT ${orcc_gen}
+    )
+    LIBUHD_APPEND_SOURCES(${orcc_gen})
+    LIBUHD_APPEND_SOURCES(
+        ${CMAKE_CURRENT_SOURCE_DIR}/convert_with_orc.cpp
+    )
+    LIBUHD_APPEND_LIBS(${ORC_LIBRARIES})
+ELSE()
+    MESSAGE(STATUS "Orc not found, disabling orc support...")
+ENDIF(ORC_FOUND AND ORCC_EXECUTABLE)
 
 ########################################################################
 # Convert types generation
diff --git a/host/lib/convert/convert_common.hpp b/host/lib/convert/convert_common.hpp
index c2ca233d9..7f513b124 100644
--- a/host/lib/convert/convert_common.hpp
+++ b/host/lib/convert/convert_common.hpp
@@ -27,7 +27,7 @@
     static void fcn( \
         const uhd::convert::input_type &inputs, \
         const uhd::convert::output_type &outputs, \
-        size_t nsamps \
+        size_t nsamps, double scale_factor \
     ); \
     UHD_STATIC_BLOCK(register_##fcn##_##prio){ \
         uhd::convert::register_converter(#fcn, fcn, prio); \
@@ -35,7 +35,7 @@
     static void fcn( \
         const uhd::convert::input_type &inputs, \
         const uhd::convert::output_type &outputs, \
-        size_t nsamps \
+        size_t nsamps, double scale_factor \
     )
 
 /***********************************************************************
@@ -50,7 +50,7 @@ typedef boost::uint32_t              item32_t;
 /***********************************************************************
  * Convert complex short buffer to items32
  **********************************************************************/
-static UHD_INLINE item32_t sc16_to_item32(sc16_t num){
+static UHD_INLINE item32_t sc16_to_item32(sc16_t num, double){
     boost::uint16_t real = num.real();
     boost::uint16_t imag = num.imag();
     return (item32_t(real) << 16) | (item32_t(imag) << 0);
@@ -59,7 +59,7 @@ static UHD_INLINE item32_t sc16_to_item32(sc16_t num){
 /***********************************************************************
  * Convert items32 buffer to complex short
  **********************************************************************/
-static UHD_INLINE sc16_t item32_to_sc16(item32_t item){
+static UHD_INLINE sc16_t item32_to_sc16(item32_t item, double){
     return sc16_t(
         boost::int16_t(item >> 16),
         boost::int16_t(item >> 0)
@@ -69,46 +69,38 @@ static UHD_INLINE sc16_t item32_to_sc16(item32_t item){
 /***********************************************************************
  * Convert complex float buffer to items32 (no swap)
  **********************************************************************/
-static const float shorts_per_float = float(32767);
-
-static UHD_INLINE item32_t fc32_to_item32(fc32_t num){
-    boost::uint16_t real = boost::int16_t(num.real()*shorts_per_float);
-    boost::uint16_t imag = boost::int16_t(num.imag()*shorts_per_float);
+static UHD_INLINE item32_t fc32_to_item32(fc32_t num, float scale_factor){
+    boost::uint16_t real = boost::int16_t(num.real()*scale_factor);
+    boost::uint16_t imag = boost::int16_t(num.imag()*scale_factor);
     return (item32_t(real) << 16) | (item32_t(imag) << 0);
 }
 
 /***********************************************************************
  * Convert items32 buffer to complex float
  **********************************************************************/
-static const float floats_per_short = float(1.0/shorts_per_float);
-
-static UHD_INLINE fc32_t item32_to_fc32(item32_t item){
+static UHD_INLINE fc32_t item32_to_fc32(item32_t item, float scale_factor){
     return fc32_t(
-        float(boost::int16_t(item >> 16)*floats_per_short),
-        float(boost::int16_t(item >> 0)*floats_per_short)
+        float(boost::int16_t(item >> 16)*scale_factor),
+        float(boost::int16_t(item >> 0)*scale_factor)
     );
 }
 
 /***********************************************************************
  * Convert complex double buffer to items32 (no swap)
  **********************************************************************/
-static const double shorts_per_double = double(32767);
-
-static UHD_INLINE item32_t fc64_to_item32(fc64_t num){
-    boost::uint16_t real = boost::int16_t(num.real()*shorts_per_double);
-    boost::uint16_t imag = boost::int16_t(num.imag()*shorts_per_double);
+static UHD_INLINE item32_t fc64_to_item32(fc64_t num, double scale_factor){
+    boost::uint16_t real = boost::int16_t(num.real()*scale_factor);
+    boost::uint16_t imag = boost::int16_t(num.imag()*scale_factor);
     return (item32_t(real) << 16) | (item32_t(imag) << 0);
 }
 
 /***********************************************************************
  * Convert items32 buffer to complex double
  **********************************************************************/
-static const double doubles_per_short = double(1.0/shorts_per_double);
-
-static UHD_INLINE fc64_t item32_to_fc64(item32_t item){
+static UHD_INLINE fc64_t item32_to_fc64(item32_t item, double scale_factor){
     return fc64_t(
-        float(boost::int16_t(item >> 16)*doubles_per_short),
-        float(boost::int16_t(item >> 0)*doubles_per_short)
+        float(boost::int16_t(item >> 16)*scale_factor),
+        float(boost::int16_t(item >> 0)*scale_factor)
     );
 }
 
diff --git a/host/lib/convert/convert_orc.orc b/host/lib/convert/convert_orc.orc
new file mode 100644
index 000000000..5450bf4db
--- /dev/null
+++ b/host/lib/convert/convert_orc.orc
@@ -0,0 +1,63 @@
+.function _convert_fc32_1_to_item32_1_nswap_orc
+.source 8 src
+.dest 4 dst
+.floatparam 4 scalar
+.temp 8 scaled
+.temp 8 converted
+.temp 4 short
+x2 mulf scaled, src, scalar
+x2 convfl converted, scaled
+x2 convlw short, converted
+swapl short, short
+x2 swapw dst, short
+
+.function _convert_fc32_1_to_item32_1_bswap_orc
+.source 8 src
+.dest 4 dst
+.floatparam 4 scalar
+.temp 8 scaled
+.temp 8 converted
+.temp 4 short
+x2 mulf scaled, src, scalar
+x2 convfl converted, scaled
+x2 convlw short, converted
+x2 swapw dst, short
+
+.function _convert_item32_1_to_fc32_1_nswap_orc
+.source 4 src
+.dest 8 dst
+.floatparam 4 scalar
+.temp 4 tmp1
+.temp 8 tmp2
+x2 swapw tmp1, src
+swapl tmp1, tmp1
+x2 convswl tmp2, tmp1
+x2 convlf tmp2, tmp2
+x2 mulf dst, tmp2, scalar
+
+.function _convert_item32_1_to_fc32_1_bswap_orc
+.source 4 src
+.dest 8 dst
+.floatparam 4 scalar
+.temp 4 tmp1
+.temp 8 tmp2
+x2 swapw tmp1, src
+x2 convswl tmp2, tmp1
+x2 convlf tmp2, tmp2
+x2 mulf dst, tmp2, scalar
+
+.function _convert_sc16_1_to_item32_1_nswap_orc
+.source 4 src
+.dest 4 dst
+.temp 4 tmp
+.floatparam 4 scalar
+swapl tmp, src
+x2 swapw dst, tmp
+
+.function _convert_item32_1_to_sc16_1_nswap_orc
+.source 4 src
+.dest 4 dst
+.floatparam 4 scalar
+.temp 4 tmp
+x2 swapw tmp, src
+swapl dst, tmp
diff --git a/host/lib/convert/convert_with_neon.cpp b/host/lib/convert/convert_with_neon.cpp
index 3d677db5b..e5f08cad9 100644
--- a/host/lib/convert/convert_with_neon.cpp
+++ b/host/lib/convert/convert_with_neon.cpp
@@ -26,7 +26,7 @@ DECLARE_CONVERTER(convert_fc32_1_to_item32_1_nswap, PRIORITY_CUSTOM){
 
     size_t i;
 
-    float32x4_t Q0 = vdupq_n_f32(shorts_per_float);
+    float32x4_t Q0 = vdupq_n_f32(float(scale_factor));
     for (i=0; i < (nsamps & ~0x03); i+=2) {
         float32x4_t Q1 = vld1q_f32(reinterpret_cast<const float *>(&input[i]));
         float32x4_t Q2 = vmulq_f32(Q1, Q0);
@@ -37,7 +37,7 @@ DECLARE_CONVERTER(convert_fc32_1_to_item32_1_nswap, PRIORITY_CUSTOM){
     }
 
     for (; i < nsamps; i++)
-        output[i] = fc32_to_item32(input[i]);
+        output[i] = fc32_to_item32(input[i], float(scale_factor));
 }
 
 DECLARE_CONVERTER(convert_item32_1_to_fc32_1_nswap, PRIORITY_CUSTOM){
@@ -46,7 +46,7 @@ DECLARE_CONVERTER(convert_item32_1_to_fc32_1_nswap, PRIORITY_CUSTOM){
 
     size_t i;
 
-    float32x4_t Q1 = vdupq_n_f32(floats_per_short);
+    float32x4_t Q1 = vdupq_n_f32(float(scale_factor));
     for (i=0; i < (nsamps & ~0x03); i+=2) {
         int16x4_t D0 = vld1_s16(reinterpret_cast<const int16_t *>(&input[i]));
         int16x4_t D1 = vrev32_s16(D0);
@@ -57,5 +57,5 @@ DECLARE_CONVERTER(convert_item32_1_to_fc32_1_nswap, PRIORITY_CUSTOM){
     }
 
     for (; i < nsamps; i++)
-        output[i] = item32_to_fc32(input[i]);
+        output[i] = item32_to_fc32(input[i], float(scale_factor));
 }
diff --git a/host/lib/convert/convert_with_orc.cpp b/host/lib/convert/convert_with_orc.cpp
new file mode 100644
index 000000000..844c2595c
--- /dev/null
+++ b/host/lib/convert/convert_with_orc.cpp
@@ -0,0 +1,54 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "convert_common.hpp"
+#include <uhd/utils/byteswap.hpp>
+
+using namespace uhd::convert;
+
+extern "C" {
+extern void _convert_fc32_1_to_item32_1_nswap_orc(void *, const void *, float, int);
+extern void _convert_fc32_1_to_item32_1_bswap_orc(void *, const void *, float, int);
+extern void _convert_item32_1_to_fc32_1_nswap_orc(void *, const void *, float, int);
+extern void _convert_item32_1_to_fc32_1_bswap_orc(void *, const void *, float, int);
+extern void _convert_sc16_1_to_item32_1_nswap_orc(void *, const void *, float, int);
+extern void _convert_item32_1_to_sc16_1_nswap_orc(void *, const void *, float, int);
+}
+
+DECLARE_CONVERTER(convert_fc32_1_to_item32_1_nswap, PRIORITY_LIBORC){
+    _convert_fc32_1_to_item32_1_nswap_orc(outputs[0], inputs[0], scale_factor, nsamps);
+}
+
+DECLARE_CONVERTER(convert_fc32_1_to_item32_1_bswap, PRIORITY_LIBORC){
+    _convert_fc32_1_to_item32_1_bswap_orc(outputs[0], inputs[0], scale_factor, nsamps);
+}
+
+DECLARE_CONVERTER(convert_item32_1_to_fc32_1_nswap, PRIORITY_LIBORC){
+    _convert_item32_1_to_fc32_1_nswap_orc(outputs[0], inputs[0], scale_factor, nsamps);
+}
+
+DECLARE_CONVERTER(convert_item32_1_to_fc32_1_bswap, PRIORITY_LIBORC){
+    _convert_item32_1_to_fc32_1_bswap_orc(outputs[0], inputs[0], scale_factor, nsamps);
+}
+
+DECLARE_CONVERTER(convert_sc16_1_to_item32_1_nswap, PRIORITY_LIBORC){
+    _convert_sc16_1_to_item32_1_nswap_orc(outputs[0], inputs[0], scale_factor, nsamps);
+}
+
+DECLARE_CONVERTER(convert_item32_1_to_sc16_1_nswap, PRIORITY_LIBORC){
+    _convert_item32_1_to_sc16_1_nswap_orc(outputs[0], inputs[0], scale_factor, nsamps);
+}
diff --git a/host/lib/convert/convert_with_sse2.cpp b/host/lib/convert/convert_with_sse2.cpp
index 96ee9134c..52beea24a 100644
--- a/host/lib/convert/convert_with_sse2.cpp
+++ b/host/lib/convert/convert_with_sse2.cpp
@@ -25,7 +25,7 @@ DECLARE_CONVERTER(convert_fc32_1_to_item32_1_nswap, PRIORITY_CUSTOM){
     const fc32_t *input = reinterpret_cast<const fc32_t *>(inputs[0]);
     item32_t *output = reinterpret_cast<item32_t *>(outputs[0]);
 
-    __m128 scalar = _mm_set_ps1(shorts_per_float);
+    __m128 scalar = _mm_set_ps1(float(scale_factor));
 
     //convert blocks of samples with intrinsics
     size_t i = 0; for (; i < (nsamps & ~0x3); i+=4){
@@ -48,7 +48,7 @@ DECLARE_CONVERTER(convert_fc32_1_to_item32_1_nswap, PRIORITY_CUSTOM){
 
     //convert remainder
     for (; i < nsamps; i++){
-        output[i] = fc32_to_item32(input[i]);
+        output[i] = fc32_to_item32(input[i], float(scale_factor));
     }
 }
 
@@ -56,7 +56,7 @@ DECLARE_CONVERTER(convert_fc32_1_to_item32_1_bswap, PRIORITY_CUSTOM){
     const fc32_t *input = reinterpret_cast<const fc32_t *>(inputs[0]);
     item32_t *output = reinterpret_cast<item32_t *>(outputs[0]);
 
-    __m128 scalar = _mm_set_ps1(shorts_per_float);
+    __m128 scalar = _mm_set_ps1(float(scale_factor));
 
     //convert blocks of samples with intrinsics
     size_t i = 0; for (; i < (nsamps & ~0x3); i+=4){
@@ -78,7 +78,7 @@ DECLARE_CONVERTER(convert_fc32_1_to_item32_1_bswap, PRIORITY_CUSTOM){
 
     //convert remainder
     for (; i < nsamps; i++){
-        output[i] = uhd::byteswap(fc32_to_item32(input[i]));
+        output[i] = uhd::byteswap(fc32_to_item32(input[i], float(scale_factor)));
     }
 }
 
@@ -86,7 +86,7 @@ DECLARE_CONVERTER(convert_item32_1_to_fc32_1_nswap, PRIORITY_CUSTOM){
     const item32_t *input = reinterpret_cast<const item32_t *>(inputs[0]);
     fc32_t *output = reinterpret_cast<fc32_t *>(outputs[0]);
 
-    __m128 scalar = _mm_set_ps1(floats_per_short/(1 << 16));
+    __m128 scalar = _mm_set_ps1(float(scale_factor)/(1 << 16));
     __m128i zeroi = _mm_setzero_si128();
 
     //convert blocks of samples with intrinsics
@@ -111,7 +111,7 @@ DECLARE_CONVERTER(convert_item32_1_to_fc32_1_nswap, PRIORITY_CUSTOM){
 
     //convert remainder
     for (; i < nsamps; i++){
-        output[i] = item32_to_fc32(input[i]);
+        output[i] = item32_to_fc32(input[i], float(scale_factor));
     }
 }
 
@@ -119,7 +119,7 @@ DECLARE_CONVERTER(convert_item32_1_to_fc32_1_bswap, PRIORITY_CUSTOM){
     const item32_t *input = reinterpret_cast<const item32_t *>(inputs[0]);
     fc32_t *output = reinterpret_cast<fc32_t *>(outputs[0]);
 
-    __m128 scalar = _mm_set_ps1(floats_per_short/(1 << 16));
+    __m128 scalar = _mm_set_ps1(float(scale_factor)/(1 << 16));
     __m128i zeroi = _mm_setzero_si128();
 
     //convert blocks of samples with intrinsics
@@ -143,6 +143,6 @@ DECLARE_CONVERTER(convert_item32_1_to_fc32_1_bswap, PRIORITY_CUSTOM){
 
     //convert remainder
     for (; i < nsamps; i++){
-        output[i] = item32_to_fc32(uhd::byteswap(input[i]));
+        output[i] = item32_to_fc32(uhd::byteswap(input[i]), float(scale_factor));
     }
 }
diff --git a/host/lib/convert/gen_convert_general.py b/host/lib/convert/gen_convert_general.py
index f03448047..8c3138bda 100644
--- a/host/lib/convert/gen_convert_general.py
+++ b/host/lib/convert/gen_convert_general.py
@@ -34,7 +34,7 @@ DECLARE_CONVERTER(convert_$(cpu_type)_1_to_item32_1_$(swap), PRIORITY_GENERAL){
     item32_t *output = reinterpret_cast<item32_t *>(outputs[0]);
 
     for (size_t i = 0; i < nsamps; i++){
-        output[i] = $(swap_fcn)($(cpu_type)_to_item32(input[i]));
+        output[i] = $(swap_fcn)($(cpu_type)_to_item32(input[i], float(scale_factor)));
     }
 }
 
@@ -43,7 +43,7 @@ DECLARE_CONVERTER(convert_item32_1_to_$(cpu_type)_1_$(swap), PRIORITY_GENERAL){
     $(cpu_type)_t *output = reinterpret_cast<$(cpu_type)_t *>(outputs[0]);
 
     for (size_t i = 0; i < nsamps; i++){
-        output[i] = item32_to_$(cpu_type)($(swap_fcn)(input[i]));
+        output[i] = item32_to_$(cpu_type)($(swap_fcn)(input[i]), float(scale_factor));
     }
 }
 """
@@ -56,7 +56,7 @@ DECLARE_CONVERTER(convert_$(cpu_type)_$(width)_to_item32_1_$(swap), PRIORITY_GEN
 
     for (size_t i = 0, j = 0; i < nsamps; i++){
         #for $w in range($width)
-        output[j++] = $(swap_fcn)($(cpu_type)_to_item32(input$(w)[i]));
+        output[j++] = $(swap_fcn)($(cpu_type)_to_item32(input$(w)[i], float(scale_factor)));
         #end for
     }
 }
@@ -69,7 +69,7 @@ DECLARE_CONVERTER(convert_item32_1_to_$(cpu_type)_$(width)_$(swap), PRIORITY_GEN
 
     for (size_t i = 0, j = 0; i < nsamps; i++){
         #for $w in range($width)
-        output$(w)[i] = item32_to_$(cpu_type)($(swap_fcn)(input[j++]));
+        output$(w)[i] = item32_to_$(cpu_type)($(swap_fcn)(input[j++]), float(scale_factor));
         #end for
     }
 }
diff --git a/host/lib/transport/CMakeLists.txt b/host/lib/transport/CMakeLists.txt
index 90360977a..b1821956c 100644
--- a/host/lib/transport/CMakeLists.txt
+++ b/host/lib/transport/CMakeLists.txt
@@ -98,5 +98,5 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/if_addrs.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/udp_simple.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/udp_zero_copy.cpp
-    ${CMAKE_CURRENT_SOURCE_DIR}/vrt_packet_handler.hpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/usb_zero_copy_wrapper.cpp
 )
diff --git a/host/lib/transport/gen_vrt_if_packet.py b/host/lib/transport/gen_vrt_if_packet.py
index 7440def6a..5f048d8c7 100755
--- a/host/lib/transport/gen_vrt_if_packet.py
+++ b/host/lib/transport/gen_vrt_if_packet.py
@@ -62,6 +62,8 @@ static pred_table_type get_pred_unpack_table(void){
         if(vrt_hdr_word & $hex(0x3 << 22)) table[i] |= $hex($tsi_p);
         if(vrt_hdr_word & $hex(0x3 << 20)) table[i] |= $hex($tsf_p);
         if(vrt_hdr_word & $hex(0x1 << 26)) table[i] |= $hex($tlr_p);
+        if(vrt_hdr_word & $hex(0x1 << 24)) table[i] |= $hex($eob_p);
+        if(vrt_hdr_word & $hex(0x1 << 25)) table[i] |= $hex($sob_p);
     }
     return table;
 }
@@ -84,9 +86,11 @@ void vrt::if_hdr_pack_$(suffix)(
     if (if_packet_info.has_tsi) pred |= $hex($tsi_p);
     if (if_packet_info.has_tsf) pred |= $hex($tsf_p);
     if (if_packet_info.has_tlr) pred |= $hex($tlr_p);
+    if (if_packet_info.eob)     pred |= $hex($eob_p);
+    if (if_packet_info.sob)     pred |= $hex($sob_p);
 
     switch(pred){
-    #for $pred in range(2**5)
+    #for $pred in range(2**7)
     case $pred:
         #set $num_header_words = 1
         #set $flags = 0
@@ -126,6 +130,13 @@ void vrt::if_hdr_pack_$(suffix)(
         #else
             #set $num_trailer_words = 0;
         #end if
+        ########## Burst Flags ##########
+        #if $pred & $eob_p
+            #set $flags |= (0x1 << 24);
+        #end if
+        #if $pred & $sob_p
+            #set $flags |= (0x1 << 25);
+        #end if
         ########## Variables ##########
             if_packet_info.num_header_words32 = $num_header_words;
             if_packet_info.num_packet_words32 = $($num_header_words + $num_trailer_words) + if_packet_info.num_payload_words32;
@@ -134,10 +145,6 @@ void vrt::if_hdr_pack_$(suffix)(
     #end for
     }
 
-    //set the burst flags
-    if (if_packet_info.sob) vrt_hdr_flags |= $hex(0x1 << 25);
-    if (if_packet_info.eob) vrt_hdr_flags |= $hex(0x1 << 24);
-
     //fill in complete header word
     packet_buff[0] = $(XE_MACRO)(boost::uint32_t(0
         | (if_packet_info.packet_type << 29)
@@ -162,13 +169,11 @@ void vrt::if_hdr_unpack_$(suffix)(
     //extract fields from the header
     if_packet_info.packet_type = if_packet_info_t::packet_type_t(vrt_hdr_word >> 29);
     if_packet_info.packet_count = (vrt_hdr_word >> 16) & 0xf;
-    //if_packet_info.sob = bool(vrt_hdr_word & $hex(0x1 << 25)); //not implemented
-    //if_packet_info.eob = bool(vrt_hdr_word & $hex(0x1 << 24)); //not implemented
 
     const pred_type pred = pred_unpack_table[pred_table_index(vrt_hdr_word)];
 
     switch(pred){
-    #for $pred in range(2**5)
+    #for $pred in range(2**7)
     case $pred:
         #set $has_time_spec = False
         #set $num_header_words = 1
@@ -215,6 +220,17 @@ void vrt::if_hdr_unpack_$(suffix)(
             if_packet_info.has_tlr = false;
             #set $num_trailer_words = 0;
         #end if
+        ########## Burst Flags ##########
+        #if $pred & $eob_p
+            if_packet_info.eob = true;
+        #else
+            if_packet_info.eob = false;
+        #end if
+        #if $pred & $sob_p
+            if_packet_info.sob = true;
+        #else
+            if_packet_info.sob = false;
+        #end if
         ########## Variables ##########
             //another failure case
             if (packet_words32 < $($num_header_words + $num_trailer_words))
@@ -243,9 +259,11 @@ if __name__ == '__main__':
     open(sys.argv[1], 'w').write(parse_tmpl(
         TMPL_TEXT,
         file=__file__,
-        sid_p = 0b00001,
-        cid_p = 0b00010,
-        tsi_p = 0b00100,
-        tsf_p = 0b01000,
-        tlr_p = 0b10000,
+        sid_p = 0b0000001,
+        cid_p = 0b0000010,
+        tsi_p = 0b0000100,
+        tsf_p = 0b0001000,
+        tlr_p = 0b0010000,
+        sob_p = 0b0100000,
+        eob_p = 0b1000000,
     ))
diff --git a/host/lib/transport/libusb1_zero_copy.cpp b/host/lib/transport/libusb1_zero_copy.cpp
index 28bea978b..19a7a3742 100644
--- a/host/lib/transport/libusb1_zero_copy.cpp
+++ b/host/lib/transport/libusb1_zero_copy.cpp
@@ -20,7 +20,7 @@
 #include <uhd/transport/bounded_buffer.hpp>
 #include <uhd/transport/buffer_pool.hpp>
 #include <uhd/utils/thread_priority.hpp>
-#include <uhd/utils/log.hpp>
+#include <uhd/utils/msg.hpp>
 #include <uhd/exception.hpp>
 #include <boost/function.hpp>
 #include <boost/foreach.hpp>
@@ -44,15 +44,24 @@ static const size_t DEFAULT_XFER_SIZE = 32*512; //bytes
  * to ensure that they are compiled with the same calling convention as libusb.
  */
 
-//! helper function: handles all async callbacks
-static void LIBUSB_CALL libusb_async_cb(libusb_transfer *lut){
+//! helper function: handles all rx async callbacks
+static void LIBUSB_CALL libusb_async_rx_cb(libusb_transfer *lut){
+    if(lut->actual_length == 0) {
+        UHD_ASSERT_THROW(libusb_submit_transfer(lut) == 0); //get out until you find some real data
+        return;
+    }
+    (*static_cast<boost::function<void()> *>(lut->user_data))();
+}
+
+//! helper function: handles all tx async callbacks
+static void LIBUSB_CALL libusb_async_tx_cb(libusb_transfer *lut) {
     (*static_cast<boost::function<void()> *>(lut->user_data))();
 }
 
 //! callback to free transfer upon cancellation
 static void LIBUSB_CALL cancel_transfer_cb(libusb_transfer *lut){
-    if (lut->status == LIBUSB_TRANSFER_CANCELLED) libusb_free_transfer(lut);
-    else UHD_LOGV(rarely) << "libusb cancel_transfer unexpected status " << lut->status << std::endl;
+    if (lut->status == LIBUSB_TRANSFER_CANCELLED || lut->status == LIBUSB_TRANSFER_TIMED_OUT) libusb_free_transfer(lut);
+    else UHD_MSG(error) << "libusb cancel_transfer unexpected status " << lut->status << std::endl;
 }
 
 /***********************************************************************
@@ -97,7 +106,7 @@ public:
     void commit(size_t len){
         if (_expired) return;
         _lut->length = len;
-        if(len == 0) libusb_async_cb(_lut);
+        if(len == 0) libusb_async_tx_cb(_lut);
         else UHD_ASSERT_THROW(libusb_submit_transfer(_lut) == 0);
         _expired = true;
     }
@@ -157,9 +166,9 @@ public:
                 (recv_endpoint & 0x7f) | 0x80,                          // endpoint
                 static_cast<unsigned char *>(_recv_buffer_pool->at(i)), // buffer
                 this->get_recv_frame_size(),                            // length
-                libusb_transfer_cb_fn(&libusb_async_cb),                // callback
+                libusb_transfer_cb_fn(&libusb_async_rx_cb),             // callback
                 static_cast<void *>(&_callbacks.back()),                // user_data
-                0                                                       // timeout
+                0                                                       // timeout (ms)
             );
 
             _all_luts.push_back(lut);
@@ -183,13 +192,13 @@ public:
                 (send_endpoint & 0x7f) | 0x00,                          // endpoint
                 static_cast<unsigned char *>(_send_buffer_pool->at(i)), // buffer
                 this->get_send_frame_size(),                            // length
-                libusb_transfer_cb_fn(&libusb_async_cb),                // callback
+                libusb_transfer_cb_fn(&libusb_async_tx_cb),             // callback
                 static_cast<void *>(&_callbacks.back()),                // user_data
                 0                                                       // timeout
             );
 
             _all_luts.push_back(lut);
-            libusb_async_cb(lut);
+            libusb_async_tx_cb(lut);
         }
 
         //spawn the event handler threads
@@ -206,7 +215,9 @@ public:
         BOOST_FOREACH(libusb_transfer *lut, _all_luts){
             lut->callback = libusb_transfer_cb_fn(&cancel_transfer_cb);
             libusb_cancel_transfer(lut);
-            while(lut->status != LIBUSB_TRANSFER_CANCELLED && lut->status != LIBUSB_TRANSFER_COMPLETED) {
+            while(lut->status != LIBUSB_TRANSFER_CANCELLED
+               && lut->status != LIBUSB_TRANSFER_COMPLETED
+               && lut->status != LIBUSB_TRANSFER_TIMED_OUT) {
                 boost::this_thread::sleep(boost::posix_time::milliseconds(10));
             }
         }
diff --git a/host/lib/transport/super_recv_packet_handler.hpp b/host/lib/transport/super_recv_packet_handler.hpp
new file mode 100644
index 000000000..80ad17b6c
--- /dev/null
+++ b/host/lib/transport/super_recv_packet_handler.hpp
@@ -0,0 +1,638 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_LIBUHD_TRANSPORT_SUPER_RECV_PACKET_HANDLER_HPP
+#define INCLUDED_LIBUHD_TRANSPORT_SUPER_RECV_PACKET_HANDLER_HPP
+
+#include <uhd/config.hpp>
+#include <uhd/exception.hpp>
+#include <uhd/convert.hpp>
+#include <uhd/device.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/utils/byteswap.hpp>
+#include <uhd/types/io_type.hpp>
+#include <uhd/types/otw_type.hpp>
+#include <uhd/types/metadata.hpp>
+#include <uhd/transport/vrt_if_packet.hpp>
+#include <uhd/transport/zero_copy.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/foreach.hpp>
+#include <boost/function.hpp>
+#include <boost/format.hpp>
+#include <iostream>
+#include <vector>
+
+namespace uhd{ namespace transport{ namespace sph{
+
+UHD_INLINE boost::uint32_t get_context_code(
+    const boost::uint32_t *vrt_hdr, const vrt::if_packet_info_t &if_packet_info
+){
+    //extract the context word (we dont know the endianness so mirror the bytes)
+    boost::uint32_t word0 = vrt_hdr[if_packet_info.num_header_words32] |
+              uhd::byteswap(vrt_hdr[if_packet_info.num_header_words32]);
+    return word0 & 0xff;
+}
+
+typedef boost::function<void(void)> handle_overflow_type;
+static inline void handle_overflow_nop(void){}
+
+/***********************************************************************
+ * Alignment indexes class:
+ *  - Access an integer set with very quick operations.
+ **********************************************************************/
+class alignment_indexes{
+public:
+    typedef boost::uint16_t index_type; //16 buffers
+
+    alignment_indexes(void):
+        _indexes(0),
+        _sizes(256, 0),
+        _fronts(256, ~0)
+    {
+        //fill the O(1) look up tables for a single byte
+        for (size_t i = 0; i < 256; i++){
+            for (size_t j = 0; j < 8; j++){
+                if (i & (1 << j)){
+                    _sizes[i]++;
+                    _fronts[i] = j;
+                }
+            }
+        }
+    }
+
+    UHD_INLINE void reset(size_t len){_indexes = (1 << len) - 1;}
+
+    UHD_INLINE size_t front(void){
+        //check one byte per iteration
+        for (size_t i = 0; i < sizeof(_indexes)*8; i+=8){
+            size_t front = _fronts[(_indexes >> i) & 0xff];
+            if (front != size_t(~0)) return front + i;
+        }
+        if (empty()) throw uhd::runtime_error("cannot call front() when empty");
+        UHD_THROW_INVALID_CODE_PATH();
+    }
+
+    UHD_INLINE void remove(size_t index){_indexes &= ~(1 << index);}
+
+    UHD_INLINE bool empty(void){return _indexes == 0;}
+
+    UHD_INLINE size_t size(void){
+        size_t size = 0;
+        //check one byte per iteration
+        for (size_t i = 0; i < sizeof(_indexes)*8; i+=8){
+            size += _sizes[(_indexes >> i) & 0xff];
+        }
+        return size;
+    }
+
+private:
+    index_type _indexes;
+    std::vector<size_t> _sizes;
+    std::vector<size_t> _fronts;
+};
+
+/***********************************************************************
+ * Super receive packet handler
+ *
+ * A receive packet handler represents a group of channels.
+ * The channel group shares a common sample rate.
+ * All channels are received in unison in recv().
+ **********************************************************************/
+class recv_packet_handler{
+public:
+    typedef boost::function<managed_recv_buffer::sptr(double)> get_buff_type;
+    typedef void(*vrt_unpacker_type)(const boost::uint32_t *, vrt::if_packet_info_t &);
+    //typedef boost::function<void(const boost::uint32_t *, vrt::if_packet_info_t &)> vrt_unpacker_type;
+
+    /*!
+     * Make a new packet handler for receive
+     * \param size the number of transport channels
+     */
+    recv_packet_handler(const size_t size = 1):
+        _queue_error_for_next_call(false),
+        _buffers_infos_index(0)
+    {
+        UHD_ASSERT_THROW(size <= sizeof(alignment_indexes::index_type)*8);
+        this->resize(size);
+        set_alignment_failure_threshold(1000);
+    }
+
+    //! Resize the number of transport channels
+    void resize(const size_t size){
+        if (this->size() == size) return;
+        _props.resize(size);
+        //re-initialize all buffers infos by re-creating the vector
+        _buffers_infos = std::vector<buffers_info_type>(4, buffers_info_type(size));
+    }
+
+    //! Get the channel width of this handler
+    size_t size(void) const{
+        return _props.size();
+    }
+
+    //! Setup the vrt unpacker function and offset
+    void set_vrt_unpacker(const vrt_unpacker_type &vrt_unpacker, const size_t header_offset_words32 = 0){
+        _vrt_unpacker = vrt_unpacker;
+        _header_offset_words32 = header_offset_words32;
+    }
+
+    /*!
+     * Set the threshold for alignment failure.
+     * How many packets throw out before giving up?
+     * \param threshold number of packets per channel
+     */
+    void set_alignment_failure_threshold(const size_t threshold){
+        _alignment_faulure_threshold = threshold*this->size();
+    }
+
+    //! Set the rate of ticks per second
+    void set_tick_rate(const double rate){
+        _tick_rate = rate;
+    }
+
+    //! Set the rate of samples per second
+    void set_samp_rate(const double rate){
+        _samp_rate = rate;
+    }
+
+    /*!
+     * Set the function to get a managed buffer.
+     * \param xport_chan which transport channel
+     * \param get_buff the getter function
+     */
+    void set_xport_chan_get_buff(const size_t xport_chan, const get_buff_type &get_buff){
+        _props.at(xport_chan).get_buff = get_buff;
+    }
+
+    /*!
+     * Setup the conversion functions (homogeneous across transports).
+     * Here, we load a table of converters for all possible io types.
+     * This makes the converter look-up an O(1) operation.
+     * \param otw_type the channel data type
+     * \param width the streams per channel (usually 1)
+     */
+    void set_converter(const uhd::otw_type_t &otw_type, const size_t width = 1){
+        _io_buffs.resize(width);
+        _converters.resize(128);
+        for (size_t io_type = 0; io_type < _converters.size(); io_type++){
+            try{
+                _converters[io_type] = uhd::convert::get_converter_otw_to_cpu(
+                    io_type_t::tid_t(io_type), otw_type, 1, width
+                );
+            }catch(const uhd::value_error &){} //we expect this, not all io_types valid...
+        }
+        _bytes_per_item = otw_type.get_sample_size();
+    }
+
+    //! Set the transport channel's overflow handler
+    void set_overflow_handler(const size_t xport_chan, const handle_overflow_type &handle_overflow){
+        _props.at(xport_chan).handle_overflow = handle_overflow;
+    }
+
+    //! Get a scoped lock object for this instance
+    boost::mutex::scoped_lock get_scoped_lock(void){
+        return boost::mutex::scoped_lock(_mutex);
+    }
+
+    /*******************************************************************
+     * Receive:
+     * The entry point for the fast-path receive calls.
+     * Dispatch into combinations of single packet receive calls.
+     ******************************************************************/
+    UHD_INLINE size_t recv(
+        const uhd::device::recv_buffs_type &buffs,
+        const size_t nsamps_per_buff,
+        uhd::rx_metadata_t &metadata,
+        const uhd::io_type_t &io_type,
+        uhd::device::recv_mode_t recv_mode,
+        double timeout
+    ){
+        boost::mutex::scoped_lock lock(_mutex);
+
+        //handle metadata queued from a previous receive
+        if (_queue_error_for_next_call){
+            _queue_error_for_next_call = false;
+            metadata = _queue_metadata;
+            //We want to allow a full buffer recv to be cut short by a timeout,
+            //but do not want to generate an inline timeout message packet.
+            if (_queue_metadata.error_code != rx_metadata_t::ERROR_CODE_TIMEOUT) return 0;
+        }
+
+        switch(recv_mode){
+
+        ////////////////////////////////////////////////////////////////
+        case uhd::device::RECV_MODE_ONE_PACKET:{
+        ////////////////////////////////////////////////////////////////
+            return recv_one_packet(buffs, nsamps_per_buff, metadata, io_type, timeout);
+        }
+
+        ////////////////////////////////////////////////////////////////
+        case uhd::device::RECV_MODE_FULL_BUFF:{
+        ////////////////////////////////////////////////////////////////
+            size_t accum_num_samps = recv_one_packet(
+                buffs, nsamps_per_buff, metadata, io_type, timeout
+            );
+
+            //first recv had an error code set, return immediately
+            if (metadata.error_code != rx_metadata_t::ERROR_CODE_NONE) return accum_num_samps;
+
+            //loop until buffer is filled or error code
+            while(accum_num_samps < nsamps_per_buff){
+                size_t num_samps = recv_one_packet(
+                    buffs, nsamps_per_buff - accum_num_samps, _queue_metadata,
+                    io_type, timeout, accum_num_samps*io_type.size
+                );
+
+                //metadata had an error code set, store for next call and return
+                if (_queue_metadata.error_code != rx_metadata_t::ERROR_CODE_NONE){
+                    _queue_error_for_next_call = true;
+                    break;
+                }
+                accum_num_samps += num_samps;
+            }
+            return accum_num_samps;
+        }
+
+        default: throw uhd::value_error("unknown recv mode");
+        }//switch(recv_mode)
+    }
+
+private:
+
+    boost::mutex _mutex;
+    vrt_unpacker_type _vrt_unpacker;
+    size_t _header_offset_words32;
+    double _tick_rate, _samp_rate;
+    bool _queue_error_for_next_call;
+    size_t _alignment_faulure_threshold;
+    rx_metadata_t _queue_metadata;
+    struct xport_chan_props_type{
+        xport_chan_props_type(void):
+            packet_count(0),
+            handle_overflow(&handle_overflow_nop)
+        {}
+        get_buff_type get_buff;
+        size_t packet_count;
+        handle_overflow_type handle_overflow;
+    };
+    std::vector<xport_chan_props_type> _props;
+    std::vector<void *> _io_buffs; //used in conversion
+    size_t _bytes_per_item; //used in conversion
+    std::vector<uhd::convert::function_type> _converters; //used in conversion
+
+    //! information stored for a received buffer
+    struct per_buffer_info_type{
+        managed_recv_buffer::sptr buff;
+        const boost::uint32_t *vrt_hdr;
+        vrt::if_packet_info_t ifpi;
+        time_spec_t time;
+        const char *copy_buff;
+    };
+
+    //!information stored for a set of aligned buffers
+    struct buffers_info_type : std::vector<per_buffer_info_type> {
+        buffers_info_type(const size_t size):
+            std::vector<per_buffer_info_type>(size),
+            alignment_time_valid(false),
+            data_bytes_to_copy(0),
+            fragment_offset_in_samps(0)
+        {
+            indexes_to_do.reset(size);
+        }
+        alignment_indexes indexes_to_do; //used in alignment logic
+        time_spec_t alignment_time; //used in alignment logic
+        bool alignment_time_valid; //used in alignment logic
+        size_t data_bytes_to_copy; //keeps track of state
+        size_t fragment_offset_in_samps; //keeps track of state
+        rx_metadata_t metadata; //packet description
+    };
+
+    //! a circular queue of buffer infos
+    std::vector<buffers_info_type> _buffers_infos;
+    size_t _buffers_infos_index;
+    buffers_info_type &get_curr_buffer_info(void){return _buffers_infos[_buffers_infos_index];}
+    buffers_info_type &get_prev_buffer_info(void){return _buffers_infos[(_buffers_infos_index + 3)%4];}
+    buffers_info_type &get_next_buffer_info(void){return _buffers_infos[(_buffers_infos_index + 1)%4];}
+    void increment_buffer_info(void){_buffers_infos_index = (_buffers_infos_index + 1)%4;}
+
+    //! possible return options for the packet receiver
+    enum packet_type{
+        PACKET_IF_DATA,
+        PACKET_TIMESTAMP_ERROR,
+        PACKET_INLINE_MESSAGE,
+        PACKET_TIMEOUT_ERROR,
+        PACKET_SEQUENCE_ERROR
+    };
+
+    /*******************************************************************
+     * Get and process a single packet from the transport:
+     * Receive a single packet at the given index.
+     * Extract all the relevant info and store.
+     * Check the info to determine the return code.
+     ******************************************************************/
+    UHD_INLINE packet_type get_and_process_single_packet(
+        const size_t index,
+        buffers_info_type &prev_buffer_info,
+        buffers_info_type &curr_buffer_info,
+        double timeout
+    ){
+        //get a single packet from the transport layer
+        managed_recv_buffer::sptr &buff = curr_buffer_info[index].buff;
+        buff = _props[index].get_buff(timeout);
+        if (buff.get() == NULL) return PACKET_TIMEOUT_ERROR;
+
+        //bounds check before extract
+        size_t num_packet_words32 = buff->size()/sizeof(boost::uint32_t);
+        if (num_packet_words32 <= _header_offset_words32){
+            throw std::runtime_error("recv buffer smaller than vrt packet offset");
+        }
+
+        //extract packet info
+        per_buffer_info_type &info = curr_buffer_info[index];
+        info.ifpi.num_packet_words32 = num_packet_words32 - _header_offset_words32;
+        info.vrt_hdr = buff->cast<const boost::uint32_t *>() + _header_offset_words32;
+        _vrt_unpacker(info.vrt_hdr, info.ifpi);
+        info.time = time_spec_t(time_t(info.ifpi.tsi), size_t(info.ifpi.tsf), _tick_rate); //assumes has_tsi and has_tsf are true
+        info.copy_buff = reinterpret_cast<const char *>(info.vrt_hdr + info.ifpi.num_header_words32);
+
+        //store the packet count for the next iteration
+        #ifndef SRPH_DONT_CHECK_SEQUENCE
+        const size_t expected_packet_count = _props[index].packet_count;
+        _props[index].packet_count = (info.ifpi.packet_count + 1)%16;
+        #endif
+
+        //--------------------------------------------------------------
+        //-- Determine return conditions:
+        //-- The order of these checks is HOLY.
+        //--------------------------------------------------------------
+
+        //1) check for out of order timestamps
+        if (info.ifpi.has_tsi and info.ifpi.has_tsf and prev_buffer_info[index].time > info.time){
+            return PACKET_TIMESTAMP_ERROR;
+        }
+
+        //2) check for inline IF message packets
+        if (info.ifpi.packet_type != vrt::if_packet_info_t::PACKET_TYPE_DATA){
+            return PACKET_INLINE_MESSAGE;
+        }
+
+        //3) check for sequence errors
+        #ifndef SRPH_DONT_CHECK_SEQUENCE
+        if (expected_packet_count != info.ifpi.packet_count){
+            return PACKET_SEQUENCE_ERROR;
+        }
+        #endif
+
+        //4) otherwise the packet is normal!
+        return PACKET_IF_DATA;
+    }
+
+    /*******************************************************************
+     * Alignment check:
+     * Check the received packet for alignment and mark accordingly.
+     ******************************************************************/
+    UHD_INLINE void alignment_check(
+        const size_t index, buffers_info_type &info
+    ){
+        //if alignment time was not valid or if the sequence id is newer:
+        //  use this index's time as the alignment time
+        //  reset the indexes list and remove this index
+        if (not info.alignment_time_valid or info[index].time > info.alignment_time){
+            info.alignment_time_valid = true;
+            info.alignment_time = info[index].time;
+            info.indexes_to_do.reset(this->size());
+            info.indexes_to_do.remove(index);
+            info.data_bytes_to_copy = info[index].ifpi.num_payload_words32*sizeof(boost::uint32_t);
+        }
+
+        //if the sequence id matches:
+        //  remove this index from the list and continue
+        else if (info[index].time == info.alignment_time){
+            info.indexes_to_do.remove(index);
+        }
+
+        //if the sequence id is older:
+        //  continue with the same index to try again
+        //else if (info[index].time < info.alignment_time)...
+    }
+
+    /*******************************************************************
+     * Get aligned buffers:
+     * Iterate through each index and try to accumulate aligned buffers.
+     * Handle all of the edge cases like inline messages and errors.
+     * The logic will throw out older packets until it finds a match.
+     ******************************************************************/
+    UHD_INLINE void get_aligned_buffs(double timeout){
+
+        increment_buffer_info(); //increment to next buffer
+        buffers_info_type &prev_info = get_prev_buffer_info();
+        buffers_info_type &curr_info = get_curr_buffer_info();
+        buffers_info_type &next_info = get_next_buffer_info();
+
+        //Loop until we get a message of an aligned set of buffers:
+        // - Receive a single packet and extract its info.
+        // - Handle the packet type yielded by the receive.
+        // - Check the timestamps for alignment conditions.
+        size_t iterations = 0;
+        while (not curr_info.indexes_to_do.empty()){
+
+            //get the index to process for this iteration
+            const size_t index = curr_info.indexes_to_do.front();
+            packet_type packet;
+
+            //receive a single packet from the transport
+            try{
+                packet = get_and_process_single_packet(
+                    index, prev_info, curr_info, timeout
+                );
+            }
+
+            //handle the case when the get packet throws
+            catch(const std::exception &e){
+                UHD_MSG(error) << boost::format(
+                    "The receive packet handler caught an exception.\n%s"
+                ) % e.what() << std::endl;
+                std::swap(curr_info, next_info); //save progress from curr -> next
+                curr_info.metadata.has_time_spec = false;
+                curr_info.metadata.time_spec = time_spec_t(0.0);
+                curr_info.metadata.more_fragments = false;
+                curr_info.metadata.fragment_offset = 0;
+                curr_info.metadata.start_of_burst = false;
+                curr_info.metadata.end_of_burst = false;
+                curr_info.metadata.error_code = rx_metadata_t::ERROR_CODE_BAD_PACKET;
+                return;
+            }
+
+            switch(packet){
+            case PACKET_IF_DATA:
+                alignment_check(index, curr_info);
+                break;
+
+            case PACKET_TIMESTAMP_ERROR:
+                //If the user changes the device time while streaming or without flushing,
+                //we can receive a packet that comes before the previous packet in time.
+                //This could cause the alignment logic to discard future received packets.
+                //Therefore, when this occurs, we reset the info to restart from scratch.
+                if (curr_info.alignment_time_valid and curr_info.alignment_time != curr_info[index].time){
+                    curr_info.alignment_time_valid = false;
+                }
+                alignment_check(index, curr_info);
+                break;
+
+            case PACKET_INLINE_MESSAGE:
+                std::swap(curr_info, next_info); //save progress from curr -> next
+                curr_info.metadata.has_time_spec = next_info[index].ifpi.has_tsi and next_info[index].ifpi.has_tsf;
+                curr_info.metadata.time_spec = next_info[index].time;
+                curr_info.metadata.more_fragments = false;
+                curr_info.metadata.fragment_offset = 0;
+                curr_info.metadata.start_of_burst = false;
+                curr_info.metadata.end_of_burst = false;
+                curr_info.metadata.error_code = rx_metadata_t::error_code_t(get_context_code(next_info[index].vrt_hdr, next_info[index].ifpi));
+                if (curr_info.metadata.error_code == rx_metadata_t::ERROR_CODE_OVERFLOW) _props[index].handle_overflow();
+                UHD_MSG(fastpath) << "O";
+                return;
+
+            case PACKET_TIMEOUT_ERROR:
+                std::swap(curr_info, next_info); //save progress from curr -> next
+                curr_info.metadata.has_time_spec = false;
+                curr_info.metadata.time_spec = time_spec_t(0.0);
+                curr_info.metadata.more_fragments = false;
+                curr_info.metadata.fragment_offset = 0;
+                curr_info.metadata.start_of_burst = false;
+                curr_info.metadata.end_of_burst = false;
+                curr_info.metadata.error_code = rx_metadata_t::ERROR_CODE_TIMEOUT;
+                return;
+
+            case PACKET_SEQUENCE_ERROR:
+                alignment_check(index, curr_info);
+                std::swap(curr_info, next_info); //save progress from curr -> next
+                curr_info.metadata.has_time_spec = prev_info.metadata.has_time_spec;
+                curr_info.metadata.time_spec = prev_info.metadata.time_spec + time_spec_t(0,
+                    prev_info[index].ifpi.num_payload_words32*sizeof(boost::uint32_t)/_bytes_per_item, _samp_rate);
+                curr_info.metadata.more_fragments = false;
+                curr_info.metadata.fragment_offset = 0;
+                curr_info.metadata.start_of_burst = false;
+                curr_info.metadata.end_of_burst = false;
+                curr_info.metadata.error_code = rx_metadata_t::ERROR_CODE_OVERFLOW;
+                UHD_MSG(fastpath) << "O";
+                return;
+
+            }
+
+            //too many iterations: detect alignment failure
+            if (iterations++ > _alignment_faulure_threshold){
+                UHD_MSG(error) << boost::format(
+                    "The receive packet handler failed to time-align packets.\n"
+                    "%u received packets were processed by the handler.\n"
+                    "However, a timestamp match could not be determined.\n"
+                ) % iterations << std::endl;
+                std::swap(curr_info, next_info); //save progress from curr -> next
+                curr_info.metadata.has_time_spec = false;
+                curr_info.metadata.time_spec = time_spec_t(0.0);
+                curr_info.metadata.more_fragments = false;
+                curr_info.metadata.fragment_offset = 0;
+                curr_info.metadata.start_of_burst = false;
+                curr_info.metadata.end_of_burst = false;
+                curr_info.metadata.error_code = rx_metadata_t::ERROR_CODE_ALIGNMENT;
+                return;
+            }
+
+        }
+
+        //set the metadata from the buffer information at index zero
+        curr_info.metadata.has_time_spec = curr_info[0].ifpi.has_tsi and curr_info[0].ifpi.has_tsf;
+        curr_info.metadata.time_spec = curr_info[0].time;
+        curr_info.metadata.more_fragments = false;
+        curr_info.metadata.fragment_offset = 0;
+        /* TODO SOB on RX not supported in hardware
+        static const int tlr_sob_flags = (1 << 21) | (1 << 9); //enable and indicator bits
+        curr_info.metadata.start_of_burst = curr_info[0].ifpi.has_tlr and (int(curr_info[0].ifpi.tlr & tlr_sob_flags) != 0);
+        */
+        curr_info.metadata.start_of_burst = false;
+        static const int tlr_eob_flags = (1 << 20) | (1 << 8); //enable and indicator bits
+        curr_info.metadata.end_of_burst   = curr_info[0].ifpi.has_tlr and (int(curr_info[0].ifpi.tlr & tlr_eob_flags) != 0);
+        curr_info.metadata.error_code = rx_metadata_t::ERROR_CODE_NONE;
+
+    }
+
+    /*******************************************************************
+     * Receive a single packet:
+     * Handles fragmentation, messages, errors, and copy-conversion.
+     * When no fragments are available, call the get aligned buffers.
+     * Then copy-convert available data into the user's IO buffers.
+     ******************************************************************/
+    UHD_INLINE size_t recv_one_packet(
+        const uhd::device::recv_buffs_type &buffs,
+        const size_t nsamps_per_buff,
+        uhd::rx_metadata_t &metadata,
+        const uhd::io_type_t &io_type,
+        double timeout,
+        const size_t buffer_offset_bytes = 0
+    ){
+        //get the next buffer if the current one has expired
+        if (get_curr_buffer_info().data_bytes_to_copy == 0){
+
+            //reset current buffer info members for reuse
+            get_curr_buffer_info().fragment_offset_in_samps = 0;
+            get_curr_buffer_info().alignment_time_valid = false;
+            get_curr_buffer_info().indexes_to_do.reset(this->size());
+
+            //perform receive with alignment logic
+            get_aligned_buffs(timeout);
+        }
+
+        buffers_info_type &info = get_curr_buffer_info();
+        metadata = info.metadata;
+
+        //interpolate the time spec (useful when this is a fragment)
+        metadata.time_spec += time_spec_t(0, info.fragment_offset_in_samps, _samp_rate);
+
+        //extract the number of samples available to copy
+        const size_t nsamps_available = info.data_bytes_to_copy/_bytes_per_item;
+        const size_t nsamps_to_copy = std::min(nsamps_per_buff*_io_buffs.size(), nsamps_available);
+        const size_t bytes_to_copy = nsamps_to_copy*_bytes_per_item;
+        const size_t nsamps_to_copy_per_io_buff = nsamps_to_copy/_io_buffs.size();
+
+        size_t buff_index = 0;
+        BOOST_FOREACH(per_buffer_info_type &buff_info, info){
+
+            //fill a vector with pointers to the io buffers
+            BOOST_FOREACH(void *&io_buff, _io_buffs){
+                io_buff = reinterpret_cast<char *>(buffs[buff_index++]) + buffer_offset_bytes;
+            }
+
+            //copy-convert the samples from the recv buffer
+            _converters[io_type.tid](buff_info.copy_buff, _io_buffs, nsamps_to_copy_per_io_buff, 1/32767.);
+
+            //update the rx copy buffer to reflect the bytes copied
+            buff_info.copy_buff += bytes_to_copy;
+        }
+        //update the copy buffer's availability
+        info.data_bytes_to_copy -= bytes_to_copy;
+
+        //setup the fragment flags and offset
+        metadata.more_fragments = info.data_bytes_to_copy != 0;
+        metadata.fragment_offset = info.fragment_offset_in_samps;
+        info.fragment_offset_in_samps += nsamps_to_copy; //set for next call
+
+        return nsamps_to_copy_per_io_buff;
+    }
+};
+
+}}} //namespace
+
+#endif /* INCLUDED_LIBUHD_TRANSPORT_SUPER_RECV_PACKET_HANDLER_HPP */
diff --git a/host/lib/transport/super_send_packet_handler.hpp b/host/lib/transport/super_send_packet_handler.hpp
new file mode 100644
index 000000000..8ebc264ef
--- /dev/null
+++ b/host/lib/transport/super_send_packet_handler.hpp
@@ -0,0 +1,287 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_LIBUHD_TRANSPORT_SUPER_SEND_PACKET_HANDLER_HPP
+#define INCLUDED_LIBUHD_TRANSPORT_SUPER_SEND_PACKET_HANDLER_HPP
+
+#include <uhd/config.hpp>
+#include <uhd/exception.hpp>
+#include <uhd/convert.hpp>
+#include <uhd/device.hpp>
+#include <uhd/utils/byteswap.hpp>
+#include <uhd/types/io_type.hpp>
+#include <uhd/types/otw_type.hpp>
+#include <uhd/types/metadata.hpp>
+#include <uhd/transport/vrt_if_packet.hpp>
+#include <uhd/transport/zero_copy.hpp>
+#include <boost/thread/thread_time.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/foreach.hpp>
+#include <boost/function.hpp>
+#include <iostream>
+#include <vector>
+
+namespace uhd{ namespace transport{ namespace sph{
+
+/***********************************************************************
+ * Super send packet handler
+ *
+ * A send packet handler represents a group of channels.
+ * The channel group shares a common sample rate.
+ * All channels are sent in unison in send().
+ **********************************************************************/
+class send_packet_handler{
+public:
+    typedef boost::function<managed_send_buffer::sptr(double)> get_buff_type;
+    typedef void(*vrt_packer_type)(boost::uint32_t *, vrt::if_packet_info_t &);
+    //typedef boost::function<void(boost::uint32_t *, vrt::if_packet_info_t &)> vrt_packer_type;
+
+    /*!
+     * Make a new packet handler for send
+     * \param size the number of transport channels
+     */
+    send_packet_handler(const size_t size = 1):
+        _next_packet_seq(0)
+    {
+        this->resize(size);
+    }
+
+    //! Resize the number of transport channels
+    void resize(const size_t size){
+        if (this->size() == size) return;
+        _props.resize(size);
+        static const boost::uint64_t zero = 0;
+        _zero_buffs.resize(size, &zero);
+    }
+
+    //! Get the channel width of this handler
+    size_t size(void) const{
+        return _props.size();
+    }
+
+    //! Setup the vrt packer function and offset
+    void set_vrt_packer(const vrt_packer_type &vrt_packer, const size_t header_offset_words32 = 0){
+        _vrt_packer = vrt_packer;
+        _header_offset_words32 = header_offset_words32;
+    }
+
+    //! Set the rate of ticks per second
+    void set_tick_rate(const double rate){
+        _tick_rate = rate;
+    }
+
+    //! Set the rate of samples per second
+    void set_samp_rate(const double rate){
+        _samp_rate = rate;
+    }
+
+    /*!
+     * Set the function to get a managed buffer.
+     * \param xport_chan which transport channel
+     * \param get_buff the getter function
+     */
+    void set_xport_chan_get_buff(const size_t xport_chan, const get_buff_type &get_buff){
+        _props.at(xport_chan).get_buff = get_buff;
+    }
+
+    /*!
+     * Setup the conversion functions (homogeneous across transports).
+     * Here, we load a table of converters for all possible io types.
+     * This makes the converter look-up an O(1) operation.
+     * \param otw_type the channel data type
+     * \param width the streams per channel (usually 1)
+     */
+    void set_converter(const uhd::otw_type_t &otw_type, const size_t width = 1){
+        _io_buffs.resize(width);
+        _converters.resize(128);
+        for (size_t io_type = 0; io_type < _converters.size(); io_type++){
+            try{
+                _converters[io_type] = uhd::convert::get_converter_cpu_to_otw(
+                    io_type_t::tid_t(io_type), otw_type, 1, width
+                );
+            }catch(const uhd::value_error &){} //we expect this, not all io_types valid...
+        }
+        _bytes_per_item = otw_type.get_sample_size();
+    }
+
+    /*!
+     * Set the maximum number of samples per host packet.
+     * Ex: A USRP1 in dual channel mode would be half.
+     * \param num_samps the maximum samples in a packet
+     */
+    void set_max_samples_per_packet(const size_t num_samps){
+        _max_samples_per_packet = num_samps;
+    }
+
+    //! Get a scoped lock object for this instance
+    boost::mutex::scoped_lock get_scoped_lock(void){
+        return boost::mutex::scoped_lock(_mutex);
+    }
+
+    /*******************************************************************
+     * Send:
+     * The entry point for the fast-path send calls.
+     * Dispatch into combinations of single packet send calls.
+     ******************************************************************/
+    UHD_INLINE size_t send(
+        const uhd::device::send_buffs_type &buffs,
+        const size_t nsamps_per_buff,
+        const uhd::tx_metadata_t &metadata,
+        const uhd::io_type_t &io_type,
+        uhd::device::send_mode_t send_mode,
+        double timeout
+    ){
+        boost::mutex::scoped_lock lock(_mutex);
+
+        //translate the metadata to vrt if packet info
+        vrt::if_packet_info_t if_packet_info;
+        if_packet_info.has_sid = false;
+        if_packet_info.has_cid = false;
+        if_packet_info.has_tlr = false;
+        if_packet_info.has_tsi = metadata.has_time_spec;
+        if_packet_info.has_tsf = metadata.has_time_spec;
+        if_packet_info.tsi     = boost::uint32_t(metadata.time_spec.get_full_secs());
+        if_packet_info.tsf     = boost::uint64_t(metadata.time_spec.get_tick_count(_tick_rate));
+        if_packet_info.sob     = metadata.start_of_burst;
+        if_packet_info.eob     = metadata.end_of_burst;
+
+        if (nsamps_per_buff <= _max_samples_per_packet) send_mode = uhd::device::SEND_MODE_ONE_PACKET;
+        switch(send_mode){
+
+        ////////////////////////////////////////////////////////////////
+        case uhd::device::SEND_MODE_ONE_PACKET:{
+        ////////////////////////////////////////////////////////////////
+
+            //TODO remove this code when sample counts of zero are supported by hardware
+            if (nsamps_per_buff == 0) return send_one_packet(
+                _zero_buffs, 1, if_packet_info, io_type, timeout
+            );
+
+            return send_one_packet(
+                buffs,
+                std::min(nsamps_per_buff, _max_samples_per_packet),
+                if_packet_info, io_type, timeout
+            );
+        }
+
+        ////////////////////////////////////////////////////////////////
+        case uhd::device::SEND_MODE_FULL_BUFF:{
+        ////////////////////////////////////////////////////////////////
+            size_t total_num_samps_sent = 0;
+
+            //false until final fragment
+            if_packet_info.eob = false;
+
+            const size_t num_fragments = (nsamps_per_buff-1)/_max_samples_per_packet;
+            const size_t final_length = ((nsamps_per_buff-1)%_max_samples_per_packet)+1;
+
+            //loop through the following fragment indexes
+            for (size_t i = 0; i < num_fragments; i++){
+
+                //send a fragment with the helper function
+                const size_t num_samps_sent = send_one_packet(
+                    buffs, _max_samples_per_packet,
+                    if_packet_info, io_type, timeout,
+                    total_num_samps_sent*io_type.size
+                );
+                total_num_samps_sent += num_samps_sent;
+                if (num_samps_sent == 0) return total_num_samps_sent;
+
+                //setup metadata for the next fragment
+                const time_spec_t time_spec = metadata.time_spec + time_spec_t(0, total_num_samps_sent, _samp_rate);
+                if_packet_info.tsi = boost::uint32_t(time_spec.get_full_secs());
+                if_packet_info.tsf = boost::uint64_t(time_spec.get_tick_count(_tick_rate));
+                if_packet_info.sob = false;
+
+            }
+
+            //send the final fragment with the helper function
+            if_packet_info.eob = metadata.end_of_burst;
+            return total_num_samps_sent + send_one_packet(
+                buffs, final_length,
+                if_packet_info, io_type, timeout,
+                total_num_samps_sent*io_type.size
+            );
+        }
+
+        default: throw uhd::value_error("unknown send mode");
+        }//switch(send_mode)
+    }
+
+private:
+
+    boost::mutex _mutex;
+    vrt_packer_type _vrt_packer;
+    size_t _header_offset_words32;
+    double _tick_rate, _samp_rate;
+    struct xport_chan_props_type{
+        get_buff_type get_buff;
+    };
+    std::vector<xport_chan_props_type> _props;
+    std::vector<const void *> _io_buffs; //used in conversion
+    size_t _bytes_per_item; //used in conversion
+    std::vector<uhd::convert::function_type> _converters; //used in conversion
+    size_t _max_samples_per_packet;
+    std::vector<const void *> _zero_buffs;
+    size_t _next_packet_seq;
+
+    /*******************************************************************
+     * Send a single packet:
+     ******************************************************************/
+    size_t send_one_packet(
+        const uhd::device::send_buffs_type &buffs,
+        const size_t nsamps_per_buff,
+        vrt::if_packet_info_t &if_packet_info,
+        const uhd::io_type_t &io_type,
+        double timeout,
+        const size_t buffer_offset_bytes = 0
+    ){
+        //load the rest of the if_packet_info in here
+        if_packet_info.num_payload_words32 = (nsamps_per_buff*_io_buffs.size()*_bytes_per_item)/sizeof(boost::uint32_t);
+        if_packet_info.packet_count = _next_packet_seq;
+
+        size_t buff_index = 0;
+        BOOST_FOREACH(xport_chan_props_type &props, _props){
+            managed_send_buffer::sptr buff = props.get_buff(timeout);
+            if (buff.get() == NULL) return 0; //timeout
+
+            //fill a vector with pointers to the io buffers
+            BOOST_FOREACH(const void *&io_buff, _io_buffs){
+                io_buff = reinterpret_cast<const char *>(buffs[buff_index++]) + buffer_offset_bytes;
+            }
+            boost::uint32_t *otw_mem = buff->cast<boost::uint32_t *>() + _header_offset_words32;
+
+            //pack metadata into a vrt header
+            _vrt_packer(otw_mem, if_packet_info);
+            otw_mem += if_packet_info.num_header_words32;
+
+            //copy-convert the samples into the send buffer
+            _converters[io_type.tid](_io_buffs, otw_mem, nsamps_per_buff, 32767.);
+
+            //commit the samples to the zero-copy interface
+            size_t num_bytes_total = (_header_offset_words32+if_packet_info.num_packet_words32)*sizeof(boost::uint32_t);
+            buff->commit(num_bytes_total);
+
+        }
+        _next_packet_seq++; //increment sequence after commits
+        return nsamps_per_buff;
+    }
+};
+
+}}} //namespace
+
+#endif /* INCLUDED_LIBUHD_TRANSPORT_SUPER_SEND_PACKET_HANDLER_HPP */
diff --git a/host/lib/transport/usb_zero_copy_wrapper.cpp b/host/lib/transport/usb_zero_copy_wrapper.cpp
new file mode 100644
index 000000000..227c4b392
--- /dev/null
+++ b/host/lib/transport/usb_zero_copy_wrapper.cpp
@@ -0,0 +1,202 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/transport/usb_zero_copy.hpp>
+#include <uhd/transport/bounded_buffer.hpp>
+#include <uhd/transport/buffer_pool.hpp>
+#include <boost/foreach.hpp>
+#include <vector>
+#include <iostream>
+
+using namespace uhd::transport;
+bool debug = true;
+
+static inline size_t next_boundary(size_t length, size_t boundary){
+    //pad to the boundary, assumes boundary is a power of 2
+    return (length + (boundary-1)) & ~(boundary-1);
+}
+
+/***********************************************************************
+ * USB zero copy wrapper - managed receive buffer
+ **********************************************************************/
+class usb_zero_copy_wrapper_mrb : public managed_recv_buffer{
+public:
+    usb_zero_copy_wrapper_mrb(bounded_buffer<usb_zero_copy_wrapper_mrb *> &queue):
+        _queue(queue){/*NOP*/}
+
+    void release(void){
+        if (_mrb.get() == NULL) return;
+        _mrb->release();
+        _queue.push_with_haste(this);
+        _mrb.reset();
+    }
+
+    sptr get_new(managed_recv_buffer::sptr mrb, const void *mem, size_t len){
+        _mrb = mrb;
+        _mem = mem;
+        _len = len;
+        return make_managed_buffer(this);
+    }
+
+private:
+    const void *get_buff(void) const{return _mem;}
+    size_t get_size(void) const{return _len;}
+
+    bounded_buffer<usb_zero_copy_wrapper_mrb *> &_queue;
+    const void *_mem;
+    size_t _len;
+    managed_recv_buffer::sptr _mrb;
+};
+
+/***********************************************************************
+ * USB zero copy wrapper - managed send buffer
+ **********************************************************************/
+class usb_zero_copy_wrapper_msb : public managed_send_buffer{
+public:
+    usb_zero_copy_wrapper_msb(bounded_buffer<usb_zero_copy_wrapper_msb *> &queue, size_t boundary):
+        _queue(queue), _boundary(boundary){/*NOP*/}
+
+    void commit(size_t len){
+        if (_msb.get() == NULL) return;
+        _msb->commit(next_boundary(len, _boundary));
+        _queue.push_with_haste(this);
+        _msb.reset();
+    }
+
+    sptr get_new(managed_send_buffer::sptr msb){
+        _msb = msb;
+        return make_managed_buffer(this);
+    }
+
+private:
+    void *get_buff(void) const{return _msb->cast<void *>();}
+    size_t get_size(void) const{return _msb->size();}
+
+    bounded_buffer<usb_zero_copy_wrapper_msb *> &_queue;
+    size_t _boundary;
+    managed_send_buffer::sptr _msb;
+};
+
+/***********************************************************************
+ * USB zero copy wrapper implementation
+ **********************************************************************/
+class usb_zero_copy_wrapper : public usb_zero_copy{
+public:
+    usb_zero_copy_wrapper(
+        sptr usb_zc, size_t usb_frame_boundary
+    ):
+        _internal_zc(usb_zc),
+        _usb_frame_boundary(usb_frame_boundary),
+        _available_recv_buffs(this->get_num_recv_frames()),
+        _available_send_buffs(this->get_num_send_frames()),
+        _mrb_pool(this->get_num_recv_frames(), usb_zero_copy_wrapper_mrb(_available_recv_buffs)),
+        _msb_pool(this->get_num_send_frames(), usb_zero_copy_wrapper_msb(_available_send_buffs, usb_frame_boundary))
+    {
+        BOOST_FOREACH(usb_zero_copy_wrapper_mrb &mrb, _mrb_pool){
+            _available_recv_buffs.push_with_haste(&mrb);
+        }
+
+        BOOST_FOREACH(usb_zero_copy_wrapper_msb &msb, _msb_pool){
+            _available_send_buffs.push_with_haste(&msb);
+        }
+    }
+
+    managed_recv_buffer::sptr get_recv_buff(double timeout){
+        //attempt to get a managed recv buffer
+        if (not _last_recv_buff.get()){
+            _last_recv_buff = _internal_zc->get_recv_buff(timeout);
+            _last_recv_offset = 0;
+        }
+
+        //attempt to get a wrapper for a managed recv buffer
+        usb_zero_copy_wrapper_mrb *wmrb = NULL;
+        if (_last_recv_buff.get() and _available_recv_buffs.pop_with_timed_wait(wmrb, timeout)){
+            //extract this packet's memory address and length in bytes
+            const char *mem = _last_recv_buff->cast<const char *>() + _last_recv_offset;
+            const boost::uint32_t *mem32 = reinterpret_cast<const boost::uint32_t *>(mem);
+            size_t len = (mem32[0] & 0xffff)*sizeof(boost::uint32_t); //length in bytes (from VRT header)
+            
+            managed_recv_buffer::sptr recv_buff; //the buffer to be returned to the user
+            
+            recv_buff = wmrb->get_new(_last_recv_buff, mem, len);
+            _last_recv_offset = next_boundary(_last_recv_offset + len, _usb_frame_boundary);
+            
+            //check if this receive buffer has been exhausted
+            if (_last_recv_offset >= _last_recv_buff->size()) {
+                _last_recv_buff.reset();
+            }
+            
+            return recv_buff;
+        }
+
+        //otherwise return a null sptr for failure
+        return managed_recv_buffer::sptr();
+    }
+
+    size_t get_num_recv_frames(void) const{
+        return _internal_zc->get_num_recv_frames();
+    }
+
+    size_t get_recv_frame_size(void) const{
+        return _internal_zc->get_recv_frame_size();
+    }
+
+    managed_send_buffer::sptr get_send_buff(double timeout){
+        managed_send_buffer::sptr send_buff = _internal_zc->get_send_buff(timeout);
+        
+        //attempt to get a wrapper for a managed send buffer
+        usb_zero_copy_wrapper_msb *wmsb = NULL;
+        if (send_buff.get() and _available_send_buffs.pop_with_haste(wmsb)){
+            return wmsb->get_new(send_buff);
+        }
+
+        //otherwise return a null sptr for failure
+        return managed_send_buffer::sptr();
+    }
+
+    size_t get_num_send_frames(void) const{
+        return _internal_zc->get_num_send_frames();
+    }
+
+    size_t get_send_frame_size(void) const{
+        return _internal_zc->get_send_frame_size();
+    }
+
+private:
+    sptr _internal_zc;
+    size_t _usb_frame_boundary;
+    bounded_buffer<usb_zero_copy_wrapper_mrb *> _available_recv_buffs;
+    bounded_buffer<usb_zero_copy_wrapper_msb *> _available_send_buffs;
+    std::vector<usb_zero_copy_wrapper_mrb> _mrb_pool;
+    std::vector<usb_zero_copy_wrapper_msb> _msb_pool;
+    
+    //buffer to store partially-received VRT packets in
+    buffer_pool::sptr _fragment_mem;
+    
+    //state for last recv buffer to create multiple managed buffers
+    managed_recv_buffer::sptr _last_recv_buff;
+    size_t _last_recv_offset;
+};
+
+/***********************************************************************
+ * USB zero copy wrapper factory function
+ **********************************************************************/
+usb_zero_copy::sptr usb_zero_copy::make_wrapper(
+    sptr usb_zc, size_t usb_frame_boundary
+){
+    return sptr(new usb_zero_copy_wrapper(usb_zc, usb_frame_boundary));
+}
diff --git a/host/lib/transport/vrt_packet_handler.hpp b/host/lib/transport/vrt_packet_handler.hpp
deleted file mode 100644
index d74b2c13c..000000000
--- a/host/lib/transport/vrt_packet_handler.hpp
+++ /dev/null
@@ -1,470 +0,0 @@
-//
-// Copyright 2010-2011 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#ifndef INCLUDED_LIBUHD_TRANSPORT_VRT_PACKET_HANDLER_HPP
-#define INCLUDED_LIBUHD_TRANSPORT_VRT_PACKET_HANDLER_HPP
-
-#include <uhd/config.hpp>
-#include <uhd/device.hpp>
-#include <uhd/exception.hpp>
-#include <uhd/utils/byteswap.hpp>
-#include <uhd/types/io_type.hpp>
-#include <uhd/types/otw_type.hpp>
-#include <uhd/types/metadata.hpp>
-#include <uhd/transport/vrt_if_packet.hpp>
-#include <uhd/convert.hpp>
-#include <uhd/transport/zero_copy.hpp>
-#include <boost/function.hpp>
-#include <stdexcept>
-#include <iostream>
-#include <vector>
-
-namespace vrt_packet_handler{
-
-//this may change in the future but its a constant for now
-static const size_t OTW_BYTES_PER_SAMP = sizeof(boost::uint32_t);
-
-template <typename T> UHD_INLINE T get_context_code(
-    const boost::uint32_t *vrt_hdr,
-    const uhd::transport::vrt::if_packet_info_t &if_packet_info
-){
-    //extract the context word (we dont know the endianness so mirror the bytes)
-    boost::uint32_t word0 = vrt_hdr[if_packet_info.num_header_words32] |
-              uhd::byteswap(vrt_hdr[if_packet_info.num_header_words32]);
-    return T(word0 & 0xff);
-}
-
-/***********************************************************************
- * vrt packet handler for recv
- **********************************************************************/
-    typedef std::vector<uhd::transport::managed_recv_buffer::sptr> managed_recv_buffs_t;
-    typedef boost::function<bool(managed_recv_buffs_t &)> get_recv_buffs_t;
-    typedef boost::function<void(size_t /*which channel*/)> handle_overflow_t;
-    typedef boost::function<void(const boost::uint32_t *, uhd::transport::vrt::if_packet_info_t &)> vrt_unpacker_t;
-
-    static inline void handle_overflow_nop(size_t){}
-
-    struct recv_state{
-        //width of the receiver in channels
-        size_t width;
-
-        //state variables to handle fragments
-        managed_recv_buffs_t managed_buffs;
-        std::vector<const boost::uint8_t *> copy_buffs;
-        size_t size_of_copy_buffs;
-        size_t fragment_offset_in_samps;
-        std::vector<void *> io_buffs;
-        std::vector<const void *> otw_buffs;
-
-        recv_state(size_t width = 1):
-            width(width),
-            managed_buffs(width),
-            copy_buffs(width, NULL),
-            size_of_copy_buffs(0),
-            fragment_offset_in_samps(0),
-            io_buffs(0) //resized later
-        {
-            /* NOP */
-        }
-    };
-
-    /*******************************************************************
-     * Unpack a received vrt header and set the copy buffer.
-     *  - helper function for vrt_packet_handler::_recv1
-     ******************************************************************/
-    static UHD_INLINE void _recv1_helper(
-        recv_state &state,
-        uhd::rx_metadata_t &metadata,
-        double tick_rate,
-        const vrt_unpacker_t &vrt_unpacker,
-        const handle_overflow_t &handle_overflow,
-        size_t vrt_header_offset_words32
-    ){
-        //vrt unpack each managed buffer
-        uhd::transport::vrt::if_packet_info_t if_packet_info;
-        for (size_t i = 0; i < state.width; i++){
-            if (state.managed_buffs[i].get() == NULL) continue; //better have a message packet coming up...
-
-            //extract packet words and check thats its enough to move on
-            size_t num_packet_words32 = state.managed_buffs[i]->size()/sizeof(boost::uint32_t);
-            if (num_packet_words32 <= vrt_header_offset_words32){
-                throw std::runtime_error("recv buffer smaller than vrt packet offset");
-            }
-
-            //unpack the vrt header into the info struct
-            const boost::uint32_t *vrt_hdr = state.managed_buffs[i]->cast<const boost::uint32_t *>() + vrt_header_offset_words32;
-            if_packet_info.num_packet_words32 = num_packet_words32 - vrt_header_offset_words32;
-            vrt_unpacker(vrt_hdr, if_packet_info);
-
-            //handle the non-data packet case and parse its contents
-            if (if_packet_info.packet_type != uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA){
-
-                metadata.error_code = get_context_code<uhd::rx_metadata_t::error_code_t>(vrt_hdr, if_packet_info);
-                if (metadata.error_code == uhd::rx_metadata_t::ERROR_CODE_OVERFLOW) handle_overflow(i);
-
-                //break to exit loop and store metadata below
-                state.size_of_copy_buffs = 0; break;
-            }
-
-            //setup the buffer to point to the data
-            state.copy_buffs[i] = reinterpret_cast<const boost::uint8_t *>(vrt_hdr + if_packet_info.num_header_words32);
-
-            //store the minimum payload length into the copy buffer length
-            size_t num_payload_bytes = if_packet_info.num_payload_words32*sizeof(boost::uint32_t);
-            if (i == 0 or state.size_of_copy_buffs > num_payload_bytes){
-                state.size_of_copy_buffs = num_payload_bytes;
-            }
-        }
-
-        //store the last vrt info into the metadata
-        metadata.has_time_spec = if_packet_info.has_tsi and if_packet_info.has_tsf;
-        metadata.time_spec = uhd::time_spec_t(
-            time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), tick_rate
-        );
-        static const int tlr_sob_flags = (1 << 21) | (1 << 9); //enable and indicator bits
-        metadata.start_of_burst = if_packet_info.has_tlr and (int(if_packet_info.tlr & tlr_sob_flags) == tlr_sob_flags);
-        static const int tlr_eob_flags = (1 << 20) | (1 << 8); //enable and indicator bits
-        metadata.end_of_burst   = if_packet_info.has_tlr and (int(if_packet_info.tlr & tlr_eob_flags) == tlr_eob_flags);
-    }
-
-    /*******************************************************************
-     * Recv data, unpack a vrt header, and copy-convert the data.
-     *  - helper function for vrt_packet_handler::recv
-     ******************************************************************/
-    static UHD_INLINE size_t _recv1(
-        recv_state &state,
-        const uhd::device::recv_buffs_type &buffs,
-        size_t offset_bytes,
-        size_t total_samps,
-        uhd::rx_metadata_t &metadata,
-        uhd::convert::function_type &converter,
-        double tick_rate,
-        const vrt_unpacker_t &vrt_unpacker,
-        const get_recv_buffs_t &get_recv_buffs,
-        const handle_overflow_t &handle_overflow,
-        size_t vrt_header_offset_words32,
-        size_t chans_per_otw_buff
-    ){
-        metadata.error_code = uhd::rx_metadata_t::ERROR_CODE_NONE;
-
-        //perform a receive if no rx data is waiting to be copied
-        if (state.size_of_copy_buffs == 0){
-            state.fragment_offset_in_samps = 0;
-            if (not get_recv_buffs(state.managed_buffs)){
-                metadata.error_code = uhd::rx_metadata_t::ERROR_CODE_TIMEOUT;
-                return 0;
-            }
-            try{
-                _recv1_helper(
-                    state, metadata, tick_rate,
-                    vrt_unpacker, handle_overflow,
-                    vrt_header_offset_words32
-                );
-            }catch(const std::exception &e){
-                state.size_of_copy_buffs = 0; //reset copy buffs size
-                std::cerr << "Error (recv): " << e.what() << std::endl;
-                metadata.error_code = uhd::rx_metadata_t::ERROR_CODE_BAD_PACKET;
-                return 0;
-            }
-        }
-        //defaults for the metadata when this is a fragment
-        else{
-            metadata.has_time_spec = false;
-            metadata.start_of_burst = false;
-            metadata.end_of_burst = false;
-        }
-
-        //extract the number of samples available to copy
-        size_t bytes_per_item = OTW_BYTES_PER_SAMP;
-        size_t nsamps_available = state.size_of_copy_buffs/bytes_per_item;
-        size_t nsamps_to_copy = std::min(total_samps*chans_per_otw_buff, nsamps_available);
-        size_t bytes_to_copy = nsamps_to_copy*bytes_per_item;
-        size_t nsamps_to_copy_per_io_buff = nsamps_to_copy/chans_per_otw_buff;
-
-        for (size_t i = 0; i < buffs.size(); i+=chans_per_otw_buff){
-
-            //fill a vector with pointers to the io buffers
-            for (size_t j = 0; j < chans_per_otw_buff; j++){
-                state.io_buffs[j] = reinterpret_cast<boost::uint8_t *>(buffs[i+j]) + offset_bytes;
-            }
-
-            //copy-convert the samples from the recv buffer
-            converter(state.copy_buffs[i], state.io_buffs, nsamps_to_copy_per_io_buff);
-
-            //update the rx copy buffer to reflect the bytes copied
-            state.copy_buffs[i] += bytes_to_copy;
-        }
-        //update the copy buffer's availability
-        state.size_of_copy_buffs -= bytes_to_copy;
-
-        //setup the fragment flags and offset
-        metadata.more_fragments = state.size_of_copy_buffs != 0;
-        metadata.fragment_offset = state.fragment_offset_in_samps;
-        state.fragment_offset_in_samps += nsamps_to_copy; //set for next call
-
-        return nsamps_to_copy_per_io_buff;
-    }
-
-    /*******************************************************************
-     * Recv vrt packets and copy convert the samples into the buffer.
-     ******************************************************************/
-    static UHD_INLINE size_t recv(
-        recv_state &state,
-        const uhd::device::recv_buffs_type &buffs,
-        const size_t total_num_samps,
-        uhd::rx_metadata_t &metadata,
-        uhd::device::recv_mode_t recv_mode,
-        const uhd::io_type_t &io_type,
-        const uhd::otw_type_t &otw_type,
-        double tick_rate,
-        const vrt_unpacker_t &vrt_unpacker,
-        const get_recv_buffs_t &get_recv_buffs,
-        const handle_overflow_t &handle_overflow = &handle_overflow_nop,
-        size_t vrt_header_offset_words32 = 0,
-        size_t chans_per_otw_buff = 1
-    ){
-        state.io_buffs.resize(chans_per_otw_buff);
-
-        uhd::convert::function_type converter(
-            uhd::convert::get_converter_otw_to_cpu(
-                io_type, otw_type, 1, chans_per_otw_buff
-        ));
-
-        switch(recv_mode){
-
-        ////////////////////////////////////////////////////////////////
-        case uhd::device::RECV_MODE_ONE_PACKET:{
-        ////////////////////////////////////////////////////////////////
-            return _recv1(
-                state,
-                buffs, 0,
-                total_num_samps,
-                metadata,
-                converter,
-                tick_rate,
-                vrt_unpacker,
-                get_recv_buffs,
-                handle_overflow,
-                vrt_header_offset_words32,
-                chans_per_otw_buff
-            );
-        }
-
-        ////////////////////////////////////////////////////////////////
-        case uhd::device::RECV_MODE_FULL_BUFF:{
-        ////////////////////////////////////////////////////////////////
-            size_t accum_num_samps = 0;
-            uhd::rx_metadata_t tmp_md;
-            while(accum_num_samps < total_num_samps){
-                size_t num_samps = _recv1(
-                    state,
-                    buffs, accum_num_samps*io_type.size,
-                    total_num_samps - accum_num_samps,
-                    (accum_num_samps == 0)? metadata : tmp_md, //only the first metadata gets kept
-                    converter,
-                    tick_rate,
-                    vrt_unpacker,
-                    get_recv_buffs,
-                    handle_overflow,
-                    vrt_header_offset_words32,
-                    chans_per_otw_buff
-                );
-                if (num_samps == 0) break; //had a recv timeout or error, break loop
-                accum_num_samps += num_samps;
-            }
-            return accum_num_samps;
-        }
-
-        default: throw std::runtime_error("unknown recv mode");
-        }//switch(recv_mode)
-    }
-
-/***********************************************************************
- * vrt packet handler for send
- **********************************************************************/
-    typedef std::vector<uhd::transport::managed_send_buffer::sptr> managed_send_buffs_t;
-    typedef boost::function<bool(managed_send_buffs_t &)> get_send_buffs_t;
-    typedef boost::function<void(boost::uint32_t *, uhd::transport::vrt::if_packet_info_t &)> vrt_packer_t;
-
-    static const boost::uint64_t zeros = 0;
-
-    struct send_state{
-        //init the expected seq number
-        size_t next_packet_seq;
-        managed_send_buffs_t managed_buffs;
-        std::vector<const void *> zero_buffs;
-        std::vector<const void *> io_buffs;
-
-        send_state(size_t width = 1):
-            next_packet_seq(0),
-            managed_buffs(width),
-            zero_buffs(width, &zeros),
-            io_buffs(0) //resized later
-        {
-            /* NOP */
-        }
-    };
-
-    /*******************************************************************
-     * Pack a vrt header, copy-convert the data, and send it.
-     *  - helper function for vrt_packet_handler::send
-     ******************************************************************/
-    static UHD_INLINE size_t _send1(
-        send_state &state,
-        const uhd::device::send_buffs_type &buffs,
-        const size_t offset_bytes,
-        const size_t num_samps,
-        uhd::transport::vrt::if_packet_info_t &if_packet_info,
-        uhd::convert::function_type &converter,
-        const vrt_packer_t &vrt_packer,
-        const get_send_buffs_t &get_send_buffs,
-        const size_t vrt_header_offset_words32,
-        const size_t chans_per_otw_buff
-    ){
-        //load the rest of the if_packet_info in here
-        if_packet_info.num_payload_words32 = (num_samps*chans_per_otw_buff*OTW_BYTES_PER_SAMP)/sizeof(boost::uint32_t);
-        if_packet_info.packet_count = state.next_packet_seq;
-
-        //get send buffers for each otw channel
-        if (not get_send_buffs(state.managed_buffs)) return 0;
-
-        for (size_t i = 0; i < buffs.size(); i+=chans_per_otw_buff){
-            //calculate pointers with offsets to io and otw memory
-            for (size_t j = 0; j < chans_per_otw_buff; j++){
-                state.io_buffs[j] = reinterpret_cast<const boost::uint8_t *>(buffs[i+j]) + offset_bytes;
-            }
-            boost::uint32_t *otw_mem = state.managed_buffs[i]->cast<boost::uint32_t *>() + vrt_header_offset_words32;
-
-            //pack metadata into a vrt header
-            vrt_packer(otw_mem, if_packet_info);
-            otw_mem += if_packet_info.num_header_words32;
-
-            //copy-convert the samples into the send buffer
-            converter(state.io_buffs, otw_mem, num_samps);
-
-            //commit the samples to the zero-copy interface
-            size_t num_bytes_total = (vrt_header_offset_words32+if_packet_info.num_packet_words32)*sizeof(boost::uint32_t);
-            state.managed_buffs[i]->commit(num_bytes_total);
-        }
-        state.next_packet_seq++; //increment sequence after commits
-        return num_samps;
-    }
-
-    /*******************************************************************
-     * Send vrt packets and copy convert the samples into the buffer.
-     ******************************************************************/
-    static UHD_INLINE size_t send(
-        send_state &state,
-        const uhd::device::send_buffs_type &buffs,
-        const size_t total_num_samps,
-        const uhd::tx_metadata_t &metadata,
-        uhd::device::send_mode_t send_mode,
-        const uhd::io_type_t &io_type,
-        const uhd::otw_type_t &otw_type,
-        double tick_rate,
-        const vrt_packer_t &vrt_packer,
-        const get_send_buffs_t &get_send_buffs,
-        size_t max_samples_per_packet,
-        size_t vrt_header_offset_words32 = 0,
-        size_t chans_per_otw_buff = 1
-    ){
-        state.io_buffs.resize(chans_per_otw_buff);
-
-        uhd::convert::function_type converter(
-            uhd::convert::get_converter_cpu_to_otw(
-                io_type, otw_type, chans_per_otw_buff, 1
-        ));
-
-        //translate the metadata to vrt if packet info
-        uhd::transport::vrt::if_packet_info_t if_packet_info;
-        if_packet_info.has_sid = false;
-        if_packet_info.has_cid = false;
-        if_packet_info.has_tlr = false;
-        if_packet_info.tsi = boost::uint32_t(metadata.time_spec.get_full_secs());
-        if_packet_info.tsf = boost::uint64_t(metadata.time_spec.get_tick_count(tick_rate));
-
-        if (total_num_samps <= max_samples_per_packet) send_mode = uhd::device::SEND_MODE_ONE_PACKET;
-        switch(send_mode){
-
-        ////////////////////////////////////////////////////////////////
-        case uhd::device::SEND_MODE_ONE_PACKET:{
-        ////////////////////////////////////////////////////////////////
-
-            //fill in parts of the packet info overwrote in full buff mode
-            if_packet_info.has_tsi = metadata.has_time_spec;
-            if_packet_info.has_tsf = metadata.has_time_spec;
-            if_packet_info.sob = metadata.start_of_burst;
-            if_packet_info.eob = metadata.end_of_burst;
-
-            return _send1(
-                state,
-                //TODO remove this code when sample counts of zero are supported by hardware
-                (total_num_samps)?buffs : state.zero_buffs, 0,
-                std::max<size_t>(1, std::min(total_num_samps, max_samples_per_packet)),
-                if_packet_info,
-                converter,
-                vrt_packer,
-                get_send_buffs,
-                vrt_header_offset_words32,
-                chans_per_otw_buff
-            );
-        }
-
-        ////////////////////////////////////////////////////////////////
-        case uhd::device::SEND_MODE_FULL_BUFF:{
-        ////////////////////////////////////////////////////////////////
-            size_t total_num_samps_sent = 0;
-
-            //loop through the following fragment indexes
-            while(total_num_samps_sent < total_num_samps){
-
-                //calculate per-loop-iteration variables
-                const size_t total_num_samps_unsent = total_num_samps - total_num_samps_sent;
-                const bool first_fragment = (total_num_samps_sent == 0);
-                const bool final_fragment = (total_num_samps_unsent <= max_samples_per_packet);
-
-                //calculate new flags for the fragments
-                if_packet_info.has_tsi = metadata.has_time_spec  and first_fragment;
-                if_packet_info.has_tsf = if_packet_info.has_tsi;
-                if_packet_info.sob     = metadata.start_of_burst and first_fragment;
-                if_packet_info.eob     = metadata.end_of_burst   and final_fragment;
-
-                //send the fragment with the helper function
-                const size_t num_samps_sent = _send1(
-                    state,
-                    buffs, total_num_samps_sent*io_type.size,
-                    std::min(total_num_samps_unsent, max_samples_per_packet),
-                    if_packet_info,
-                    converter,
-                    vrt_packer,
-                    get_send_buffs,
-                    vrt_header_offset_words32,
-                    chans_per_otw_buff
-                );
-                total_num_samps_sent += num_samps_sent;
-                if (num_samps_sent == 0) return total_num_samps_sent;
-            }
-            return total_num_samps_sent;
-        }
-
-        default: throw std::runtime_error("unknown send mode");
-        }//switch(send_mode)
-    }
-
-} //namespace vrt_packet_handler
-
-#endif /* INCLUDED_LIBUHD_TRANSPORT_VRT_PACKET_HANDLER_HPP */
diff --git a/host/lib/usrp/CMakeLists.txt b/host/lib/usrp/CMakeLists.txt
index 281910735..80f4bf45e 100644
--- a/host/lib/usrp/CMakeLists.txt
+++ b/host/lib/usrp/CMakeLists.txt
@@ -37,4 +37,5 @@ INCLUDE_SUBDIRECTORY(dboard)
 INCLUDE_SUBDIRECTORY(fx2)
 INCLUDE_SUBDIRECTORY(usrp1)
 INCLUDE_SUBDIRECTORY(usrp2)
+INCLUDE_SUBDIRECTORY(b100)
 INCLUDE_SUBDIRECTORY(usrp_e100)
diff --git a/host/lib/usrp/b100/CMakeLists.txt b/host/lib/usrp/b100/CMakeLists.txt
new file mode 100644
index 000000000..e1618a49c
--- /dev/null
+++ b/host/lib/usrp/b100/CMakeLists.txt
@@ -0,0 +1,47 @@
+#
+# Copyright 2010-2011 Ettus Research LLC
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+########################################################################
+# This file included, use CMake directory variables
+########################################################################
+
+########################################################################
+# Conditionally configure the B100 support
+########################################################################
+LIBUHD_REGISTER_COMPONENT("B100" ENABLE_B100 ON "ENABLE_LIBUHD;ENABLE_USB" OFF)
+
+IF(ENABLE_B100)
+    LIBUHD_APPEND_SOURCES(
+        ${CMAKE_CURRENT_SOURCE_DIR}/clock_ctrl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/clock_ctrl.hpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/codec_ctrl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/codec_ctrl.hpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/codec_impl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/ctrl_packet.hpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/dboard_impl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/dboard_iface.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/dsp_impl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/io_impl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/mboard_impl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/b100_ctrl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/b100_ctrl.hpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/b100_iface.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/b100_iface.hpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/b100_impl.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/b100_impl.hpp
+    )
+ENDIF(ENABLE_B100)
diff --git a/host/lib/usrp/b100/b100_ctrl.cpp b/host/lib/usrp/b100/b100_ctrl.cpp
new file mode 100644
index 000000000..4d4520e1e
--- /dev/null
+++ b/host/lib/usrp/b100/b100_ctrl.cpp
@@ -0,0 +1,245 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "../../transport/super_recv_packet_handler.hpp"
+#include "b100_ctrl.hpp"
+#include "b100_impl.hpp"
+#include <uhd/transport/usb_zero_copy.hpp>
+#include <uhd/transport/zero_copy.hpp>
+#include <uhd/transport/vrt_if_packet.hpp>
+#include <uhd/utils/thread_priority.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/types/metadata.hpp>
+#include <uhd/types/serial.hpp>
+#include "ctrl_packet.hpp"
+#include <boost/thread.hpp>
+#include <uhd/exception.hpp>
+
+using namespace uhd::transport;
+using namespace uhd;
+
+bool b100_ctrl_debug = false;
+
+class b100_ctrl_impl : public b100_ctrl {
+public:
+    b100_ctrl_impl(uhd::transport::usb_zero_copy::sptr ctrl_transport) : 
+        sync_ctrl_fifo(2),
+        async_msg_fifo(100),
+        _ctrl_transport(ctrl_transport),
+        _seq(0)
+    {
+        boost::barrier spawn_barrier(2);
+        viking_marauders.create_thread(boost::bind(&b100_ctrl_impl::viking_marauder_loop, this, boost::ref(spawn_barrier)));
+        spawn_barrier.wait();
+    }
+    
+    int write(boost::uint32_t addr, const ctrl_data_t &data);
+    ctrl_data_t read(boost::uint32_t addr, size_t len);
+    
+    ~b100_ctrl_impl(void) {
+        bbl_out_marauding = false;
+        viking_marauders.interrupt_all();
+        viking_marauders.join_all();
+    }
+    
+    bool get_ctrl_data(ctrl_data_t &pkt_data, double timeout);
+    bool recv_async_msg(uhd::async_metadata_t &async_metadata, double timeout);
+    
+private:
+    int send_pkt(boost::uint16_t *cmd);
+    
+    //änd hërë wë gö ä-Vïkïng för äsynchronous control packets
+    void viking_marauder_loop(boost::barrier &);
+    bounded_buffer<ctrl_data_t> sync_ctrl_fifo;
+    bounded_buffer<async_metadata_t> async_msg_fifo;
+    boost::thread_group viking_marauders;
+    bool bbl_out_marauding;
+    
+    uhd::transport::usb_zero_copy::sptr _ctrl_transport;
+    boost::uint8_t _seq;
+};
+
+/***********************************************************************
+ * helper functions for packing/unpacking control packets
+ **********************************************************************/
+void pack_ctrl_pkt(boost::uint16_t *pkt_buff,
+                          const ctrl_pkt_t &pkt){
+    //first two bits are OP
+    //next six bits are CALLBACKS
+    //next 8 bits are SEQUENCE
+    //next 16 bits are LENGTH (16-bit word)
+    //next 32 bits are ADDRESS (16-bit word LSW)
+    //then DATA (28 16-bit words)
+    pkt_buff[0] = (boost::uint16_t(pkt.pkt_meta.op) << 14) | (boost::uint16_t(pkt.pkt_meta.callbacks) << 8) | pkt.pkt_meta.seq;
+    pkt_buff[1] = pkt.pkt_meta.len;
+    pkt_buff[2] = (pkt.pkt_meta.addr & 0x00000FFF);
+    pkt_buff[3] = 0x0000; //address high bits always 0 on this device
+    
+    for(size_t i = 0; i < pkt.data.size(); i++) {
+        pkt_buff[4+i] = pkt.data[i];
+    }
+}
+
+void unpack_ctrl_pkt(const boost::uint16_t *pkt_buff,
+                            ctrl_pkt_t &pkt){
+    pkt.pkt_meta.seq = pkt_buff[0] & 0xFF;
+    pkt.pkt_meta.op = CTRL_PKT_OP_READ; //really this is useless
+    pkt.pkt_meta.len = pkt_buff[1];
+    pkt.pkt_meta.callbacks = 0; //callbacks aren't implemented yet
+    pkt.pkt_meta.addr = pkt_buff[2] | boost::uint32_t(pkt_buff[3] << 16);
+    
+    //let's check this so we don't go pushing 64K of crap onto the pkt
+    if(pkt.pkt_meta.len > CTRL_PACKET_DATA_LENGTH) {
+        throw uhd::runtime_error("Received control packet too long");
+    }
+
+    for(int i = 4; i < 4+pkt.pkt_meta.len; i++) pkt.data.push_back(pkt_buff[i]);
+}
+
+int b100_ctrl_impl::send_pkt(boost::uint16_t *cmd) {
+    managed_send_buffer::sptr sbuf = _ctrl_transport->get_send_buff();
+    if(!sbuf.get()) {
+        throw uhd::runtime_error("Control channel send error");
+    }
+        
+    //FIXME there's a better way to do this
+    for(size_t i = 0; i < (CTRL_PACKET_LENGTH / sizeof(boost::uint16_t)); i++) {
+        sbuf->cast<boost::uint16_t *>()[i] = cmd[i];
+    }
+    sbuf->commit(CTRL_PACKET_LENGTH); //fixed size transaction
+    return 0;
+}
+
+int b100_ctrl_impl::write(boost::uint32_t addr, const ctrl_data_t &data) {
+    UHD_ASSERT_THROW(data.size() <= (CTRL_PACKET_DATA_LENGTH / sizeof(boost::uint16_t)));
+    ctrl_pkt_t pkt;
+    pkt.data = data;
+    pkt.pkt_meta.op = CTRL_PKT_OP_WRITE;
+    pkt.pkt_meta.callbacks = 0;
+    pkt.pkt_meta.seq = _seq++;
+    pkt.pkt_meta.len = pkt.data.size();
+    pkt.pkt_meta.addr = addr;
+    boost::uint16_t pkt_buff[CTRL_PACKET_LENGTH / sizeof(boost::uint16_t)];
+        
+    pack_ctrl_pkt(pkt_buff, pkt);
+    size_t result = send_pkt(pkt_buff);
+    return result;
+}
+
+ctrl_data_t b100_ctrl_impl::read(boost::uint32_t addr, size_t len) {
+    UHD_ASSERT_THROW(len <= (CTRL_PACKET_DATA_LENGTH / sizeof(boost::uint16_t)));
+
+    ctrl_pkt_t pkt;
+    pkt.pkt_meta.op = CTRL_PKT_OP_READ;
+    pkt.pkt_meta.callbacks = 0;
+    pkt.pkt_meta.seq = _seq++;
+    pkt.pkt_meta.len = len;
+    pkt.pkt_meta.addr = addr;
+    boost::uint16_t pkt_buff[CTRL_PACKET_LENGTH / sizeof(boost::uint16_t)];
+
+    pack_ctrl_pkt(pkt_buff, pkt);
+    send_pkt(pkt_buff);
+    
+    //loop around waiting for the response to appear
+    while(!get_ctrl_data(pkt.data, 0.05));
+
+    return pkt.data;
+}
+
+/***********************************************************************
+ * Viking marauders go pillaging for asynchronous control packets in the
+ * control response endpoint. Sync packets go in sync_ctrl_fifo,
+ * async TX error messages go in async_msg_fifo. sync_ctrl_fifo should
+ * never have more than 1 message in it, since it's expected that we'll
+ * wait for a control operation to finish before starting another one.
+ **********************************************************************/
+void b100_ctrl_impl::viking_marauder_loop(boost::barrier &spawn_barrier) {
+    bbl_out_marauding = true;
+    spawn_barrier.wait();
+    set_thread_priority_safe();
+    
+    while(bbl_out_marauding){
+        managed_recv_buffer::sptr rbuf = _ctrl_transport->get_recv_buff();
+        if(!rbuf.get()) continue; //that's ok, there are plenty of villages to pillage!
+        const boost::uint16_t *pkt_buf = rbuf->cast<const boost::uint16_t *>();
+        
+        if(pkt_buf[0] >> 8 == CTRL_PACKET_HEADER_MAGIC) {
+            //so it's got a control packet header, let's parse it.
+            ctrl_pkt_t pkt;
+            unpack_ctrl_pkt(pkt_buf, pkt);
+        
+            if(pkt.pkt_meta.seq != boost::uint8_t(_seq - 1)) {
+                throw uhd::runtime_error("Sequence error on control channel");
+            }
+            if(pkt.pkt_meta.len > (CTRL_PACKET_LENGTH - CTRL_PACKET_HEADER_LENGTH)) {
+                throw uhd::runtime_error("Control channel packet length too long");
+            }
+        
+            //push it onto the queue
+            sync_ctrl_fifo.push_with_wait(pkt.data);
+        } else { //it's an async status pkt
+            //extract the vrt header packet info
+            vrt::if_packet_info_t if_packet_info;
+            if_packet_info.num_packet_words32 = rbuf->size()/sizeof(boost::uint32_t);
+            const boost::uint32_t *vrt_hdr = rbuf->cast<const boost::uint32_t *>();
+            vrt::if_hdr_unpack_le(vrt_hdr, if_packet_info);
+            
+            if(    if_packet_info.sid == 0 
+               and if_packet_info.packet_type != vrt::if_packet_info_t::PACKET_TYPE_DATA){
+                //fill in the async metadata
+                async_metadata_t metadata;
+                metadata.channel = 0;
+                metadata.has_time_spec = if_packet_info.has_tsi and if_packet_info.has_tsf;
+                metadata.time_spec = time_spec_t(
+                    time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), 64e6 //FIXME get from clock_ctrl
+                );
+                metadata.event_code = async_metadata_t::event_code_t(sph::get_context_code(vrt_hdr, if_packet_info));
+                //print the famous U, and push the metadata into the message queue
+                if (metadata.event_code & 
+                    ( async_metadata_t::EVENT_CODE_UNDERFLOW 
+                    | async_metadata_t::EVENT_CODE_UNDERFLOW_IN_PACKET) )
+                    UHD_MSG(fastpath) << "U";
+                    
+                if (metadata.event_code & 
+                    ( async_metadata_t::EVENT_CODE_SEQ_ERROR
+                    | async_metadata_t::EVENT_CODE_SEQ_ERROR_IN_BURST) )
+                    UHD_MSG(fastpath) << "S";
+                    
+                async_msg_fifo.push_with_pop_on_full(metadata);
+                continue;
+            }
+            throw uhd::runtime_error("Control: unknown async response");
+        }
+    }
+}
+
+bool b100_ctrl_impl::get_ctrl_data(ctrl_data_t &pkt_data, double timeout){
+    boost::this_thread::disable_interruption di; //disable because the wait can throw
+    return sync_ctrl_fifo.pop_with_timed_wait(pkt_data, timeout);
+}
+
+bool b100_ctrl_impl::recv_async_msg(uhd::async_metadata_t &async_metadata, double timeout) {
+    boost::this_thread::disable_interruption di; //disable because the wait can throw
+    return async_msg_fifo.pop_with_timed_wait(async_metadata, timeout);
+}
+
+/***********************************************************************
+ * Public make function for b100_ctrl interface
+ **********************************************************************/
+b100_ctrl::sptr b100_ctrl::make(uhd::transport::usb_zero_copy::sptr ctrl_transport){
+    return sptr(new b100_ctrl_impl(ctrl_transport));
+}
diff --git a/host/lib/usrp/b100/b100_ctrl.hpp b/host/lib/usrp/b100/b100_ctrl.hpp
new file mode 100644
index 000000000..ae706dbb4
--- /dev/null
+++ b/host/lib/usrp/b100/b100_ctrl.hpp
@@ -0,0 +1,69 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_B100_CTRL_HPP
+#define INCLUDED_B100_CTRL_HPP
+
+#include <uhd/transport/bounded_buffer.hpp>
+#include <uhd/transport/usb_zero_copy.hpp>
+#include <uhd/types/metadata.hpp>
+#include <uhd/types/serial.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/utility.hpp>
+#include "ctrl_packet.hpp"
+#include <boost/thread.hpp>
+
+class b100_ctrl : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<b100_ctrl> sptr;
+
+    /*!
+     * Make a USRP control object from a data transport
+     * \param ctrl_transport a USB data transport
+     * \return a new b100 control object
+     */
+    static sptr make(uhd::transport::usb_zero_copy::sptr ctrl_transport);
+
+    /*!
+     * Write a byte vector to an FPGA register
+     * \param addr the FPGA register address
+     * \param bytes the data to write
+     * \return 0 on success, error code on failure
+     */
+    virtual int write(boost::uint32_t addr, const ctrl_data_t &data) = 0;
+
+    /*!
+     * Read a byte vector from an FPGA register (blocking read)
+     * \param addr the FPGA register address
+     * \param len the length of the read
+     * \return a vector of bytes from the register(s) in question
+     */
+    virtual ctrl_data_t read(boost::uint32_t addr, size_t len) = 0;
+
+    /*!
+     * Get a sync ctrl packet (blocking)
+     * \param the packet data buffer
+     * \param the timeout value
+     * \return true if it got something
+     */
+    virtual bool get_ctrl_data(ctrl_data_t &pkt_data, double timeout) = 0;
+    
+    virtual bool recv_async_msg(uhd::async_metadata_t &async_metadata, double timeout) = 0;
+    
+};
+
+#endif /* INCLUDED_B100_CTRL_HPP */
diff --git a/host/lib/usrp/b100/b100_iface.cpp b/host/lib/usrp/b100/b100_iface.cpp
new file mode 100644
index 000000000..17ea2e6ad
--- /dev/null
+++ b/host/lib/usrp/b100/b100_iface.cpp
@@ -0,0 +1,336 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_iface.hpp"
+#include "usrp_commands.h"
+#include <uhd/exception.hpp>
+#include <uhd/utils/byteswap.hpp>
+#include <uhd/utils/safe_call.hpp>
+#include <uhd/utils/msg.hpp>
+#include <boost/format.hpp>
+#include <iomanip>
+#include <iostream>
+
+//FOR TESTING ONLY
+#include "b100_regs.hpp"
+#include <boost/thread/thread.hpp>
+#include "usrp_i2c_addr.h"
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace uhd::transport;
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+static const bool iface_debug = true;
+static const boost::uint16_t USRP_B_FW_COMPAT_NUM = 0x02;
+static const boost::uint16_t USRP_B_FPGA_COMPAT_NUM = 0x03;
+
+/***********************************************************************
+ * I2C + FX2 implementation wrapper
+ **********************************************************************/
+class b100_i2c_fx2_iface : public i2c_iface{
+public:
+    b100_i2c_fx2_iface(uhd::usrp::fx2_ctrl::sptr fx2_ctrl){
+        _fx2_ctrl = fx2_ctrl;
+    }
+
+    void write_i2c(boost::uint8_t addr, const byte_vector_t &bytes)
+    {
+        UHD_ASSERT_THROW(bytes.size() < max_i2c_data_bytes);
+
+        unsigned char buff[max_i2c_data_bytes];
+        std::copy(bytes.begin(), bytes.end(), buff);
+
+        int ret = _fx2_ctrl->usrp_i2c_write(addr & 0xff,
+                                             buff,
+                                             bytes.size());
+
+        if (iface_debug && (ret < 0))
+            uhd::runtime_error("USRP: failed i2c write");
+    }
+
+    byte_vector_t read_i2c(boost::uint8_t addr, size_t num_bytes)
+    {
+      UHD_ASSERT_THROW(num_bytes < max_i2c_data_bytes);
+
+      unsigned char buff[max_i2c_data_bytes];
+      int ret = _fx2_ctrl->usrp_i2c_read(addr & 0xff,
+                                            buff,
+                                            num_bytes);
+
+      if (iface_debug && ((ret < 0) || (unsigned)ret < (num_bytes)))
+          uhd::runtime_error("USRP: failed i2c read");
+
+      byte_vector_t out_bytes;
+      for (size_t i = 0; i < num_bytes; i++)
+          out_bytes.push_back(buff[i]);
+
+      return out_bytes;
+    }
+
+private:
+    static const size_t max_i2c_data_bytes = 64;
+    uhd::usrp::fx2_ctrl::sptr _fx2_ctrl;
+};
+
+/***********************************************************************
+ * USRP-E100 interface implementation
+ **********************************************************************/
+class b100_iface_impl : public b100_iface{
+public:
+    /*******************************************************************
+     * Structors
+     ******************************************************************/
+    b100_iface_impl(uhd::usrp::fx2_ctrl::sptr fx2_ctrl,
+                      b100_ctrl::sptr fpga_ctrl) :
+                      _fx2_i2c_iface(fx2_ctrl),
+                      _fx2_ctrl(fx2_ctrl),
+                      _fpga_ctrl(fpga_ctrl)
+    {
+        this->check_fw_compat();
+        if (fpga_ctrl.get() != NULL){
+            enable_gpif(1);
+            i2c_init();
+            this->check_fpga_compat();
+        }
+        mb_eeprom = mboard_eeprom_t(get_fx2_i2c_iface(), mboard_eeprom_t::MAP_B000);
+    }
+
+    void check_fw_compat(void){
+        unsigned char data[4]; //useless data buffer
+        const boost::uint16_t fw_compat_num = _fx2_ctrl->usrp_control_read(
+            VRQ_FW_COMPAT, 0, 0, data, sizeof(data)
+        );
+        if (fw_compat_num != USRP_B_FW_COMPAT_NUM){
+            throw uhd::runtime_error(str(boost::format(
+                "Expected firmware compatibility number 0x%x, but got 0x%x:\n"
+                "The firmware build is not compatible with the host code build."
+            ) % USRP_B_FW_COMPAT_NUM % fw_compat_num));
+        }
+    }
+
+    void check_fpga_compat(void){
+        const boost::uint16_t fpga_compat_num = this->peek16(B100_REG_MISC_COMPAT);
+        if (fpga_compat_num != USRP_B_FPGA_COMPAT_NUM){
+            throw uhd::runtime_error(str(boost::format(
+                "Expected FPGA compatibility number 0x%x, but got 0x%x:\n"
+                "The FPGA build is not compatible with the host code build."
+            ) % USRP_B_FPGA_COMPAT_NUM % fpga_compat_num));
+        }
+    }
+
+    ~b100_iface_impl(void)
+    {
+        /* NOP */
+    }
+
+    /*******************************************************************
+     * Peek and Poke
+     ******************************************************************/
+
+    void poke(boost::uint32_t addr, const ctrl_data_t &data) {
+        boost::mutex::scoped_lock lock(_ctrl_mutex);
+        _fpga_ctrl->write(addr, data);
+    }
+
+    ctrl_data_t peek(boost::uint32_t addr, size_t len) {
+        boost::mutex::scoped_lock lock(_ctrl_mutex);
+        return _fpga_ctrl->read(addr, len);
+    }
+
+    void poke16(boost::uint32_t addr, boost::uint16_t value)
+    {
+        ctrl_data_t words(1);
+        words[0] = value;
+        poke(addr, words);
+    }
+
+    void poke32(boost::uint32_t addr, boost::uint32_t value)
+    {
+        //just a subset of poke() to maintain compatibility
+        ctrl_data_t words(2);
+        words[0] = value & 0x0000FFFF;
+        words[1] = value >> 16;
+        poke(addr, words);
+    }
+
+    boost::uint32_t peek32(boost::uint32_t addr)
+    {
+        ctrl_data_t words = peek(addr, 2);
+        return boost::uint32_t((boost::uint32_t(words[1]) << 16) | words[0]);
+    }
+
+    boost::uint16_t peek16(boost::uint32_t addr)
+    {
+        ctrl_data_t words = peek(addr, 1);
+        return boost::uint16_t(words[0]);
+    }
+
+    /*******************************************************************
+     * I2C
+     ******************************************************************/
+    static const boost::uint32_t i2c_datarate = 400000;
+    static const boost::uint32_t wishbone_clk = 64000000; //FIXME should go somewhere else
+
+    void i2c_init(void) {
+        //init I2C FPGA interface.
+        poke16(B100_REG_I2C_CTRL, 0x0000);
+        //set prescalers to operate at 400kHz: WB_CLK is 64MHz...
+        boost::uint16_t prescaler = wishbone_clk / (i2c_datarate*5) - 1;
+        poke16(B100_REG_I2C_PRESCALER_LO, prescaler & 0xFF);
+        poke16(B100_REG_I2C_PRESCALER_HI, (prescaler >> 8) & 0xFF);
+        poke16(B100_REG_I2C_CTRL, I2C_CTRL_EN); //enable I2C core
+    }
+
+    static const size_t max_i2c_data_bytes = 64;
+
+    void i2c_wait_for_xfer(void)
+    {
+        while(this->peek16(B100_REG_I2C_CMD_STATUS) & I2C_ST_TIP)
+            boost::this_thread::sleep(boost::posix_time::milliseconds(10));
+    }
+
+    bool wait_chk_ack(void) {
+        i2c_wait_for_xfer();
+        return (this->peek16(B100_REG_I2C_CMD_STATUS) & I2C_ST_RXACK) == 0;
+    }
+
+    void write_i2c(boost::uint8_t addr, const byte_vector_t &bytes)
+    {
+        poke16(B100_REG_I2C_DATA, (addr << 1) | 0); //addr and read bit (0)
+        poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_WR | I2C_CMD_START | (bytes.size() == 0 ? I2C_CMD_STOP : 0));
+
+        //wait for previous transfer to complete
+        if(!wait_chk_ack()) {
+            poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_STOP);
+            return;
+        }
+
+        for(size_t i = 0; i < bytes.size(); i++) {
+            poke16(B100_REG_I2C_DATA, bytes[i]);
+            poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_WR | ((i == (bytes.size() - 1)) ? I2C_CMD_STOP : 0));
+            if(!wait_chk_ack()) {
+                poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_STOP);
+                return;
+            }
+        }
+    }
+
+    byte_vector_t read_i2c(boost::uint8_t addr, size_t num_bytes)
+    {
+        byte_vector_t bytes;
+        if(num_bytes == 0) return bytes;
+
+        while (peek16(B100_REG_I2C_CMD_STATUS) & I2C_ST_BUSY);
+
+        poke16(B100_REG_I2C_DATA, (addr << 1) | 1); //addr and read bit (1)
+        poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_WR | I2C_CMD_START);
+        //wait for previous transfer to complete
+        if(!wait_chk_ack()) {
+            poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_STOP);
+        }
+
+        for(; num_bytes > 0; num_bytes--) {
+            poke16(B100_REG_I2C_CMD_STATUS, I2C_CMD_RD | ((num_bytes == 1) ? (I2C_CMD_STOP | I2C_CMD_NACK) : 0));
+            i2c_wait_for_xfer();
+            boost::uint8_t readback = peek16(B100_REG_I2C_DATA) & 0xFF;
+            bytes.push_back(readback);
+        }
+        return bytes;
+    }
+
+    i2c_iface &get_fx2_i2c_iface(void){
+        return _fx2_i2c_iface;
+    }
+
+    /*******************************************************************
+     * SPI interface
+     * Eventually this will be replaced with a control-channel system
+     * to let the firmware do the actual write/readback cycles.
+     * This keeps the bandwidth on the control channel down.
+     ******************************************************************/
+
+    void spi_wait(void) {
+        while(peek32(B100_REG_SPI_CTRL) & SPI_CTRL_GO_BSY);
+    }
+
+    boost::uint32_t transact_spi(int which_slave,
+                                 const spi_config_t &config,
+                                 boost::uint32_t bits,
+                                 size_t num_bits,
+                                 bool readback)
+    {
+        UHD_ASSERT_THROW((num_bits <= 32) && !(num_bits % 8));
+
+        int edge_flags = ((config.miso_edge==spi_config_t::EDGE_FALL) ? SPI_CTRL_RXNEG : 0) |
+                         ((config.mosi_edge==spi_config_t::EDGE_FALL) ? 0 : SPI_CTRL_TXNEG)
+                         ;
+
+        boost::uint16_t ctrl = SPI_CTRL_ASS | (SPI_CTRL_CHAR_LEN_MASK & num_bits) | edge_flags;
+
+        poke16(B100_REG_SPI_DIV, 0x0001); // = fpga_clk / 4
+        poke32(B100_REG_SPI_SS, which_slave & 0xFFFF);
+        poke32(B100_REG_SPI_TXRX0, bits);
+        poke16(B100_REG_SPI_CTRL, ctrl);
+
+        poke16(B100_REG_SPI_CTRL, ctrl | SPI_CTRL_GO_BSY);
+        if(readback) {
+            spi_wait();
+            return peek32(B100_REG_SPI_TXRX0);
+        }
+        else {
+            return 0;
+        }
+    }
+
+    void reset_gpif(boost::uint16_t ep) {
+        _fx2_ctrl->usrp_control_write(VRQ_RESET_GPIF, ep, ep, 0, 0);
+    }
+
+    void enable_gpif(bool en) {
+        _fx2_ctrl->usrp_control_write(VRQ_ENABLE_GPIF, en ? 1 : 0, 0, 0, 0);
+    }
+
+    void clear_fpga_fifo(void) {
+        _fx2_ctrl->usrp_control_write(VRQ_CLEAR_FPGA_FIFO, 0, 0, 0, 0);
+    }
+
+    void write_uart(boost::uint8_t, const std::string &) {
+        throw uhd::not_implemented_error("Unhandled command write_uart()");
+    }
+    
+    std::string read_uart(boost::uint8_t) {
+        throw uhd::not_implemented_error("Unhandled command read_uart()");
+    }
+
+private:
+    b100_i2c_fx2_iface _fx2_i2c_iface;
+    uhd::usrp::fx2_ctrl::sptr _fx2_ctrl;
+    b100_ctrl::sptr _fpga_ctrl;
+    boost::mutex _ctrl_mutex;
+};
+
+/***********************************************************************
+ * Public Make Function
+ **********************************************************************/
+b100_iface::sptr b100_iface::make(uhd::usrp::fx2_ctrl::sptr fx2_ctrl,
+                                      b100_ctrl::sptr fpga_ctrl)
+{
+    return b100_iface::sptr(new b100_iface_impl(fx2_ctrl, fpga_ctrl));
+}
diff --git a/host/lib/usrp/b100/b100_iface.hpp b/host/lib/usrp/b100/b100_iface.hpp
new file mode 100644
index 000000000..57ed6a45c
--- /dev/null
+++ b/host/lib/usrp/b100/b100_iface.hpp
@@ -0,0 +1,73 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_B100_IFACE_HPP
+#define INCLUDED_B100_IFACE_HPP
+
+#include <uhd/usrp/mboard_iface.hpp>
+#include <uhd/usrp/mboard_eeprom.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/utility.hpp>
+#include <uhd/transport/usb_zero_copy.hpp>
+#include "../fx2/fx2_ctrl.hpp"
+#include "b100_ctrl.hpp"
+
+/*!
+ * The usrp1 interface class:
+ * Provides a set of functions to implementation layer.
+ * Including spi, peek, poke, control...
+ */
+class b100_iface : boost::noncopyable, public uhd::usrp::mboard_iface{
+public:
+    typedef boost::shared_ptr<b100_iface> sptr;
+
+    /*!
+     * Make a new b100 interface with the control transport.
+     * \param fx2_ctrl the usrp control object
+     * \param fpga_ctrl the FPGA interface control object
+     * \return a new usrp1 interface object
+     */
+    static sptr make(uhd::usrp::fx2_ctrl::sptr fx2_ctrl,
+                     b100_ctrl::sptr fpga_ctrl = b100_ctrl::sptr()
+    );
+
+    /*!
+     * Reset the GPIF interface on the FX2
+     * \param which endpoint to reset
+     * \return
+     */
+    virtual void reset_gpif(boost::uint16_t ep) = 0;
+
+    /*!
+     * Clear the GPIF FIFOs on the FPGA
+     * \return
+     */
+    virtual void clear_fpga_fifo(void) = 0;
+
+    /*!
+     * Enable/disable the GPIF interfaces on the FX2
+     * \return
+     */
+    virtual void enable_gpif(bool en) = 0;
+
+    //! Get access to the FX2 I2C interface
+    virtual uhd::i2c_iface &get_fx2_i2c_iface(void) = 0;
+
+    uhd::usrp::mboard_eeprom_t mb_eeprom;
+};
+
+#endif /* INCLUDED_USRP1_IFACE_HPP */
diff --git a/host/lib/usrp/b100/b100_impl.cpp b/host/lib/usrp/b100/b100_impl.cpp
new file mode 100644
index 000000000..7e733ddd9
--- /dev/null
+++ b/host/lib/usrp/b100/b100_impl.cpp
@@ -0,0 +1,280 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_impl.hpp"
+#include "b100_ctrl.hpp"
+#include "fpga_regs_standard.h"
+#include "usrp_spi_defs.h"
+#include <uhd/transport/usb_control.hpp>
+#include "ctrl_packet.hpp"
+#include <uhd/usrp/device_props.hpp>
+#include <uhd/usrp/mboard_props.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/exception.hpp>
+#include <uhd/utils/static.hpp>
+#include <uhd/utils/images.hpp>
+#include <uhd/utils/safe_call.hpp>
+#include <boost/format.hpp>
+#include <boost/assign/list_of.hpp>
+#include <boost/filesystem.hpp>
+#include <boost/thread/thread.hpp>
+#include <boost/lexical_cast.hpp>
+#include "b100_regs.hpp"
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace uhd::transport;
+
+const boost::uint16_t B100_VENDOR_ID  = 0x2500;
+const boost::uint16_t B100_PRODUCT_ID = 0x0001;
+const boost::uint16_t FX2_VENDOR_ID    = 0x04b4;
+const boost::uint16_t FX2_PRODUCT_ID   = 0x8613;
+
+/***********************************************************************
+ * Discovery
+ **********************************************************************/
+static device_addrs_t b100_find(const device_addr_t &hint)
+{
+    device_addrs_t b100_addrs;
+
+    //return an empty list of addresses when type is set to non-b100
+    if (hint.has_key("type") and hint["type"] != "b100") return b100_addrs;
+
+    //Return an empty list of addresses when an address is specified,
+    //since an address is intended for a different, non-USB, device.
+    if (hint.has_key("addr")) return b100_addrs;
+
+    boost::uint16_t vid = hint.has_key("uninit") ? FX2_VENDOR_ID : B100_VENDOR_ID;
+    boost::uint16_t pid = hint.has_key("uninit") ? FX2_PRODUCT_ID : B100_PRODUCT_ID;
+
+    // Important note:
+    // The get device list calls are nested inside the for loop.
+    // This allows the usb guts to decontruct when not in use,
+    // so that re-enumeration after fw load can occur successfully.
+    // This requirement is a courtesy of libusb1.0 on windows.
+
+    //find the usrps and load firmware
+    BOOST_FOREACH(usb_device_handle::sptr handle, usb_device_handle::get_device_list(vid, pid)) {
+        //extract the firmware path for the b100
+        std::string b100_fw_image;
+        try{
+            b100_fw_image = find_image_path(hint.get("fw", "usrp_b100_fw.ihx"));
+        }
+        catch(...){
+            UHD_MSG(warning) << boost::format(
+                "Could not locate B100 firmware.\n"
+                "Please install the images package.\n"
+            );
+            return b100_addrs;
+        }
+        UHD_LOG << "the  firmware image: " << b100_fw_image << std::endl;
+
+        usb_control::sptr control;
+        try{control = usb_control::make(handle);}
+        catch(const uhd::exception &){continue;} //ignore claimed
+
+        fx2_ctrl::make(control)->usrp_load_firmware(b100_fw_image);
+    }
+
+    //get descriptors again with serial number, but using the initialized VID/PID now since we have firmware
+    vid = B100_VENDOR_ID;
+    pid = B100_PRODUCT_ID;
+
+    BOOST_FOREACH(usb_device_handle::sptr handle, usb_device_handle::get_device_list(vid, pid)) {
+        device_addr_t new_addr;
+        new_addr["type"] = "b100";
+
+        //Attempt to read the name from the EEPROM and perform filtering.
+        //This operation can throw due to compatibility mismatch.
+        try{
+            usb_control::sptr control = usb_control::make(handle);
+            b100_iface::sptr iface = b100_iface::make(fx2_ctrl::make(control));
+            new_addr["name"] = iface->mb_eeprom["name"];
+            new_addr["serial"] = handle->get_serial();
+        }
+        catch(const uhd::exception &){
+            //set these values as empty string so the device may still be found
+            //and the filter's below can still operate on the discovered device
+            new_addr["name"] = "";
+            new_addr["serial"] = "";
+        }
+
+        //this is a found b100 when the hint serial and name match or blank
+        if (
+            (not hint.has_key("name")   or hint["name"]   == new_addr["name"]) and
+            (not hint.has_key("serial") or hint["serial"] == new_addr["serial"])
+        ){
+            b100_addrs.push_back(new_addr);
+        }
+    }
+
+    return b100_addrs;
+}
+
+/***********************************************************************
+ * Make
+ **********************************************************************/
+static device::sptr b100_make(const device_addr_t &device_addr){
+
+    //extract the FPGA path for the B100
+    std::string b100_fpga_image = find_image_path(
+        device_addr.has_key("fpga")? device_addr["fpga"] : "usrp_b100_fpga.bin"
+    );
+
+    //try to match the given device address with something on the USB bus
+    std::vector<usb_device_handle::sptr> device_list =
+        usb_device_handle::get_device_list(B100_VENDOR_ID, B100_PRODUCT_ID);
+
+    //locate the matching handle in the device list
+    usb_device_handle::sptr handle;
+    BOOST_FOREACH(usb_device_handle::sptr dev_handle, device_list) {
+        if (dev_handle->get_serial() == device_addr["serial"]){
+            handle = dev_handle;
+            break;
+        }
+    }
+    UHD_ASSERT_THROW(handle.get() != NULL); //better be found
+
+    //create control objects and a data transport
+    usb_control::sptr fx2_transport = usb_control::make(handle);
+    fx2_ctrl::sptr fx2_ctrl = fx2_ctrl::make(fx2_transport);
+    fx2_ctrl->usrp_load_fpga(b100_fpga_image);
+
+    device_addr_t data_xport_args;
+    data_xport_args["recv_frame_size"] = device_addr.get("recv_frame_size", "16384");
+    data_xport_args["num_recv_frames"] = device_addr.get("num_recv_frames", "16");
+    data_xport_args["send_frame_size"] = device_addr.get("send_frame_size", "16384");
+    data_xport_args["num_send_frames"] = device_addr.get("num_send_frames", "16");
+
+    usb_zero_copy::sptr data_transport = usb_zero_copy::make_wrapper(
+        usb_zero_copy::make(
+            handle,        // identifier
+            6,             // IN endpoint
+            2,             // OUT endpoint
+            data_xport_args    // param hints
+        )
+    );
+
+    //create the control transport
+    device_addr_t ctrl_xport_args;
+    ctrl_xport_args["recv_frame_size"] = boost::lexical_cast<std::string>(CTRL_PACKET_LENGTH);
+    ctrl_xport_args["num_recv_frames"] = "16";
+    ctrl_xport_args["send_frame_size"] = boost::lexical_cast<std::string>(CTRL_PACKET_LENGTH);
+    ctrl_xport_args["num_send_frames"] = "4";
+
+    usb_zero_copy::sptr ctrl_transport = usb_zero_copy::make(
+        handle,
+        8,
+        4,
+        ctrl_xport_args
+    );
+
+    const double master_clock_rate = device_addr.cast<double>("master_clock_rate", 64e6);
+
+
+    //create the b100 implementation guts
+    return device::sptr(new b100_impl(data_transport, ctrl_transport, fx2_ctrl, master_clock_rate));
+}
+
+UHD_STATIC_BLOCK(register_b100_device){
+    device::register_device(&b100_find, &b100_make);
+}
+
+/***********************************************************************
+ * Structors
+ **********************************************************************/
+b100_impl::b100_impl(uhd::transport::usb_zero_copy::sptr data_transport,
+                         uhd::transport::usb_zero_copy::sptr ctrl_transport,
+                         uhd::usrp::fx2_ctrl::sptr fx2_ctrl,
+                         const double master_clock_rate)
+ : _data_transport(data_transport), _fx2_ctrl(fx2_ctrl)
+{
+    //this is the handler object for FPGA control packets
+    _fpga_ctrl = b100_ctrl::make(ctrl_transport);
+
+    _iface = b100_iface::make(_fx2_ctrl, _fpga_ctrl);
+
+    //create clock interface
+    _clock_ctrl = b100_clock_ctrl::make(_iface, master_clock_rate);
+
+    //create codec interface
+    _codec_ctrl = b100_codec_ctrl::make(_iface);
+
+    //initialize the codecs
+    codec_init();
+
+    //initialize the mboard
+    mboard_init();
+
+    //initialize the dboards
+    dboard_init();
+
+    //initialize the dsps
+    rx_ddc_init();
+
+    //initialize the dsps
+    tx_duc_init();
+
+    //init the subdev specs
+    this->mboard_set(MBOARD_PROP_RX_SUBDEV_SPEC, subdev_spec_t());
+    this->mboard_set(MBOARD_PROP_TX_SUBDEV_SPEC, subdev_spec_t());
+
+    //initialize the send/recv buffs
+    io_init();
+}
+
+b100_impl::~b100_impl(void){
+    /* NOP */
+}
+
+bool b100_impl::recv_async_msg(uhd::async_metadata_t &md, double timeout){
+    return _fpga_ctrl->recv_async_msg(md, timeout);
+}
+
+/***********************************************************************
+ * Device Get
+ **********************************************************************/
+void b100_impl::get(const wax::obj &key_, wax::obj &val)
+{
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<device_prop_t>()){
+    case DEVICE_PROP_NAME:
+        val = std::string("USRP-B100 device");
+        return;
+
+    case DEVICE_PROP_MBOARD:
+        UHD_ASSERT_THROW(key.name == "");
+        val = _mboard_proxy->get_link();
+        return;
+
+    case DEVICE_PROP_MBOARD_NAMES:
+        val = prop_names_t(1, ""); //vector of size 1 with empty string
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * Device Set
+ **********************************************************************/
+void b100_impl::set(const wax::obj &, const wax::obj &)
+{
+    UHD_THROW_PROP_SET_ERROR();
+}
diff --git a/host/lib/usrp/b100/b100_impl.hpp b/host/lib/usrp/b100/b100_impl.hpp
new file mode 100644
index 000000000..daec70bca
--- /dev/null
+++ b/host/lib/usrp/b100/b100_impl.hpp
@@ -0,0 +1,204 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_iface.hpp"
+#include "b100_ctrl.hpp"
+#include "clock_ctrl.hpp"
+#include "codec_ctrl.hpp"
+#include <uhd/device.hpp>
+#include <uhd/utils/pimpl.hpp>
+#include <uhd/types/dict.hpp>
+#include <uhd/types/otw_type.hpp>
+#include <uhd/types/clock_config.hpp>
+#include <uhd/types/stream_cmd.hpp>
+#include <uhd/usrp/dboard_id.hpp>
+#include <uhd/usrp/subdev_spec.hpp>
+#include <uhd/usrp/dboard_eeprom.hpp>
+#include <uhd/usrp/dboard_manager.hpp>
+#include <uhd/transport/usb_zero_copy.hpp>
+
+#ifndef INCLUDED_B100_IMPL_HPP
+#define INCLUDED_B100_IMPL_HPP
+
+/*!
+ * Make a b100 dboard interface.
+ * \param iface the b100 interface object
+ * \param clock the clock control interface
+ * \param codec the codec control interface
+ * \return a sptr to a new dboard interface
+ */
+uhd::usrp::dboard_iface::sptr make_b100_dboard_iface(
+    b100_iface::sptr iface,
+    b100_clock_ctrl::sptr clock,
+    b100_codec_ctrl::sptr codec
+);
+
+/*!
+ * Simple wax obj proxy class:
+ * Provides a wax obj interface for a set and a get function.
+ * This allows us to create nested properties structures
+ * while maintaining flattened code within the implementation.
+ */
+class wax_obj_proxy : public wax::obj {
+public:
+    typedef boost::function<void(const wax::obj &, wax::obj &)>       get_t;
+    typedef boost::function<void(const wax::obj &, const wax::obj &)> set_t;
+    typedef boost::shared_ptr<wax_obj_proxy> sptr;
+
+    static sptr make(const get_t &get, const set_t &set){
+        return sptr(new wax_obj_proxy(get, set));
+    }
+
+private:
+    get_t _get; set_t _set;
+    wax_obj_proxy(const get_t &get, const set_t &set): _get(get), _set(set) {};
+    void get(const wax::obj &key, wax::obj &val) {return _get(key, val);}
+    void set(const wax::obj &key, const wax::obj &val) {return _set(key, val);}
+};
+
+/*!
+ * USRP1 implementation guts:
+ * The implementation details are encapsulated here.
+ * Handles properties on the mboard, dboard, dsps...
+ */
+class b100_impl : public uhd::device {
+public:
+    //structors
+    b100_impl(uhd::transport::usb_zero_copy::sptr data_transport,
+                uhd::transport::usb_zero_copy::sptr ctrl_transport,
+                uhd::usrp::fx2_ctrl::sptr fx2_ctrl,
+                double master_clock_rate);
+
+    ~b100_impl(void);
+
+    //the io interface
+    size_t send(const send_buffs_type &,
+                size_t,
+                const uhd::tx_metadata_t &,
+                const uhd::io_type_t &,
+                send_mode_t, double);
+
+    size_t recv(const recv_buffs_type &,
+                size_t, uhd::rx_metadata_t &,
+                const uhd::io_type_t &,
+                recv_mode_t, double);
+
+    size_t get_max_send_samps_per_packet(void) const;
+
+    size_t get_max_recv_samps_per_packet(void) const;
+
+    bool recv_async_msg(uhd::async_metadata_t &, double);
+
+private:
+    //clock control
+    b100_clock_ctrl::sptr _clock_ctrl;
+
+    //interface to ioctls and file descriptor
+    b100_iface::sptr _iface;
+
+    //handle io stuff
+    uhd::transport::zero_copy_if::sptr _data_transport;
+    UHD_PIMPL_DECL(io_impl) _io_impl;
+    void update_transport_channel_mapping(void);
+    void io_init(void);
+    void issue_stream_cmd(const uhd::stream_cmd_t &stream_cmd);
+    void handle_overrun(size_t);
+
+    //otw types
+    uhd::otw_type_t _recv_otw_type;
+    uhd::otw_type_t _send_otw_type;
+
+    //configuration shadows
+    uhd::clock_config_t _clock_config;
+    uhd::usrp::subdev_spec_t _rx_subdev_spec, _tx_subdev_spec;
+
+    //ad9862 codec control interface
+    b100_codec_ctrl::sptr _codec_ctrl;
+
+    //codec properties interfaces
+    void codec_init(void);
+    void rx_codec_get(const wax::obj &, wax::obj &);
+    void rx_codec_set(const wax::obj &, const wax::obj &);
+    void tx_codec_get(const wax::obj &, wax::obj &);
+    void tx_codec_set(const wax::obj &, const wax::obj &);
+    wax_obj_proxy::sptr _rx_codec_proxy, _tx_codec_proxy;
+
+    //device functions and settings
+    void get(const wax::obj &, wax::obj &);
+    void set(const wax::obj &, const wax::obj &);
+
+    //mboard functions and settings
+    void mboard_init(void);
+    void mboard_get(const wax::obj &, wax::obj &);
+    void mboard_set(const wax::obj &, const wax::obj &);
+    void update_clock_config(void);
+    wax_obj_proxy::sptr _mboard_proxy;
+    
+    /*!
+     * Make a usrp1 dboard interface.
+     * \param iface the usrp1 interface object
+     * \param clock the clock control interface
+     * \param codec the codec control interface
+     * \param dboard_slot the slot identifier
+     * \param rx_dboard_id the db id for the rx board (used for evil dbsrx purposes)
+     * \return a sptr to a new dboard interface
+     */
+    static uhd::usrp::dboard_iface::sptr make_dboard_iface(
+        b100_iface::sptr iface,
+        b100_clock_ctrl::sptr clock,
+        b100_codec_ctrl::sptr codec,
+        const uhd::usrp::dboard_id_t &rx_dboard_id
+    );
+
+    //xx dboard functions and settings
+    void dboard_init(void);
+    uhd::usrp::dboard_manager::sptr _dboard_manager;
+    uhd::usrp::dboard_iface::sptr _dboard_iface;
+
+    //rx dboard functions and settings
+    uhd::usrp::dboard_eeprom_t _rx_db_eeprom;
+    void rx_dboard_get(const wax::obj &, wax::obj &);
+    void rx_dboard_set(const wax::obj &, const wax::obj &);
+    wax_obj_proxy::sptr _rx_dboard_proxy;
+
+    //tx dboard functions and settings
+    uhd::usrp::dboard_eeprom_t _tx_db_eeprom, _gdb_eeprom;
+    void tx_dboard_get(const wax::obj &, wax::obj &);
+    void tx_dboard_set(const wax::obj &, const wax::obj &);
+    wax_obj_proxy::sptr _tx_dboard_proxy;
+
+    //rx ddc functions and settings
+    void rx_ddc_init(void);
+    void rx_ddc_get(const wax::obj &, wax::obj &);
+    void rx_ddc_set(const wax::obj &, const wax::obj &);
+    double _ddc_freq; size_t _ddc_decim;
+    wax_obj_proxy::sptr _rx_ddc_proxy;
+
+    //tx duc functions and settings
+    void tx_duc_init(void);
+    void tx_duc_get(const wax::obj &, wax::obj &);
+    void tx_duc_set(const wax::obj &, const wax::obj &);
+    double _duc_freq; size_t _duc_interp;
+    wax_obj_proxy::sptr _tx_duc_proxy;
+
+    //transports
+    b100_ctrl::sptr _fpga_ctrl;
+    uhd::usrp::fx2_ctrl::sptr _fx2_ctrl;
+
+};
+
+#endif /* INCLUDED_b100_IMPL_HPP */
diff --git a/host/lib/usrp/b100/b100_regs.hpp b/host/lib/usrp/b100/b100_regs.hpp
new file mode 100644
index 000000000..010df283e
--- /dev/null
+++ b/host/lib/usrp/b100/b100_regs.hpp
@@ -0,0 +1,264 @@
+
+
+////////////////////////////////////////////////////////////////
+//
+//         Memory map for wishbone bus
+//
+////////////////////////////////////////////////////////////////
+
+// All addresses are byte addresses.  All accesses are word (16-bit) accesses.
+//  This means that address bit 0 is usually 0.
+//  There are 11 bits of address for the control.
+
+#ifndef __B100_REGS_H
+#define __B100_REGS_H
+
+/////////////////////////////////////////////////////
+// Slave pointers
+
+#define B100_REG_SLAVE(n) ((n)<<7)
+#define B100_REG_SR_ADDR(n) ((B100_REG_SETTINGS_BASE) + (4*(n)))
+
+/////////////////////////////////////////////////////
+// Slave 0 -- Misc Regs
+
+#define B100_REG_MISC_BASE B100_REG_SLAVE(0)
+
+#define B100_REG_MISC_LED        B100_REG_MISC_BASE + 0
+#define B100_REG_MISC_SW         B100_REG_MISC_BASE + 2
+#define B100_REG_MISC_CGEN_CTRL  B100_REG_MISC_BASE + 4
+#define B100_REG_MISC_CGEN_ST    B100_REG_MISC_BASE + 6
+#define B100_REG_MISC_TEST       B100_REG_MISC_BASE + 8
+#define B100_REG_MISC_RX_LEN     B100_REG_MISC_BASE + 10
+#define B100_REG_MISC_TX_LEN     B100_REG_MISC_BASE + 12
+#define B100_REG_MISC_XFER_RATE  B100_REG_MISC_BASE + 14
+#define B100_REG_MISC_COMPAT     B100_REG_MISC_BASE + 16
+
+/////////////////////////////////////////////////////
+// Slave 1 -- UART
+//   CLKDIV is 16 bits, others are only 8
+
+#define B100_REG_UART_BASE B100_REG_SLAVE(1)
+
+#define B100_REG_UART_CLKDIV  B100_REG_UART_BASE + 0
+#define B100_REG_UART_TXLEVEL B100_REG_UART_BASE + 2
+#define B100_REG_UART_RXLEVEL B100_REG_UART_BASE + 4
+#define B100_REG_UART_TXCHAR  B100_REG_UART_BASE + 6
+#define B100_REG_UART_RXCHAR  B100_REG_UART_BASE + 8
+
+/////////////////////////////////////////////////////
+// Slave 2 -- SPI Core
+//these are 32-bit registers mapped onto the 16-bit Wishbone bus. 
+//Using peek32/poke32 should allow transparent use of these registers.
+#define B100_REG_SPI_BASE B100_REG_SLAVE(2)
+#define B100_REG_SPI_TXRX0 B100_REG_SPI_BASE + 0
+#define B100_REG_SPI_TXRX1 B100_REG_SPI_BASE + 4
+#define B100_REG_SPI_TXRX2 B100_REG_SPI_BASE + 8
+#define B100_REG_SPI_TXRX3 B100_REG_SPI_BASE + 12
+#define B100_REG_SPI_CTRL  B100_REG_SPI_BASE + 16
+#define B100_REG_SPI_DIV   B100_REG_SPI_BASE + 20
+#define B100_REG_SPI_SS    B100_REG_SPI_BASE + 24
+
+//spi slave constants
+#define B100_SPI_SS_AD9862    (1 << 2)
+#define B100_SPI_SS_TX_DB     (1 << 1)
+#define B100_SPI_SS_RX_DB     (1 << 0)
+
+//spi ctrl register bit definitions
+#define SPI_CTRL_ASS      (1<<13)
+#define SPI_CTRL_IE       (1<<12)
+#define SPI_CTRL_LSB      (1<<11)
+#define SPI_CTRL_TXNEG    (1<<10) //mosi edge, push on falling edge when 1
+#define SPI_CTRL_RXNEG    (1<< 9) //miso edge, latch on falling edge when 1
+#define SPI_CTRL_GO_BSY   (1<< 8)
+#define SPI_CTRL_CHAR_LEN_MASK 0x7F
+
+////////////////////////////////////////////////
+// Slave 3 -- I2C Core
+
+#define B100_REG_I2C_BASE B100_REG_SLAVE(3)
+#define B100_REG_I2C_PRESCALER_LO B100_REG_I2C_BASE + 0
+#define B100_REG_I2C_PRESCALER_HI B100_REG_I2C_BASE + 2
+#define B100_REG_I2C_CTRL         B100_REG_I2C_BASE + 4
+#define B100_REG_I2C_DATA         B100_REG_I2C_BASE + 6
+#define B100_REG_I2C_CMD_STATUS   B100_REG_I2C_BASE + 8
+
+//and while we're here...
+
+//
+// STA, STO, RD, WR, and IACK bits are cleared automatically
+//
+
+#define	I2C_CTRL_EN	(1 << 7)	// core enable
+#define	I2C_CTRL_IE	(1 << 6)	// interrupt enable
+
+#define	I2C_CMD_START	(1 << 7)	// generate (repeated) start condition
+#define I2C_CMD_STOP	(1 << 6)	// generate stop condition
+#define	I2C_CMD_RD	(1 << 5)	// read from slave
+#define I2C_CMD_WR	(1 << 4)	// write to slave
+#define	I2C_CMD_NACK	(1 << 3)	// when a rcvr, send ACK (ACK=0) or NACK (ACK=1)
+#define I2C_CMD_RSVD_2	(1 << 2)	// reserved
+#define	I2C_CMD_RSVD_1	(1 << 1)	// reserved
+#define I2C_CMD_IACK	(1 << 0)	// set to clear pending interrupt
+
+#define I2C_ST_RXACK	(1 << 7)	// Received acknowledgement from slave (1 = NAK, 0 = ACK)
+#define	I2C_ST_BUSY	(1 << 6)	// 1 after START signal detected; 0 after STOP signal detected
+#define	I2C_ST_AL	(1 << 5)	// Arbitration lost.  1 when core lost arbitration
+#define	I2C_ST_RSVD_4	(1 << 4)	// reserved
+#define	I2C_ST_RSVD_3	(1 << 3)	// reserved
+#define	I2C_ST_RSVD_2	(1 << 2)	// reserved
+#define I2C_ST_TIP	(1 << 1)	// Transfer-in-progress
+#define	I2C_ST_IP	(1 << 0)	// Interrupt pending
+
+////////////////////////////////////////////////
+// Slave 4 -- GPIO
+
+#define B100_REG_GPIO_BASE B100_REG_SLAVE(4)
+
+#define B100_REG_GPIO_RX_IO      B100_REG_GPIO_BASE + 0
+#define B100_REG_GPIO_TX_IO      B100_REG_GPIO_BASE + 2
+#define B100_REG_GPIO_RX_DDR     B100_REG_GPIO_BASE + 4
+#define B100_REG_GPIO_TX_DDR     B100_REG_GPIO_BASE + 6
+#define B100_REG_GPIO_RX_SEL     B100_REG_GPIO_BASE + 8
+#define B100_REG_GPIO_TX_SEL     B100_REG_GPIO_BASE + 10
+#define B100_REG_GPIO_RX_DBG     B100_REG_GPIO_BASE + 12
+#define B100_REG_GPIO_TX_DBG     B100_REG_GPIO_BASE + 14
+
+//possible bit values for sel when dbg is 0:
+#define GPIO_SEL_SW    0 // if pin is an output, set by software in the io reg
+#define GPIO_SEL_ATR   1 // if pin is an output, set by ATR logic
+
+//possible bit values for sel when dbg is 1:
+#define GPIO_SEL_DEBUG_0   0 // if pin is an output, debug lines from FPGA fabric
+#define GPIO_SEL_DEBUG_1   1 // if pin is an output, debug lines from FPGA fabric
+
+///////////////////////////////////////////////////
+// Slave 6 -- ATR Controller
+//   16 regs
+
+#define B100_REG_ATR_BASE  B100_REG_SLAVE(6)
+
+#define	B100_REG_ATR_IDLE_RXSIDE  B100_REG_ATR_BASE + 0
+#define	B100_REG_ATR_IDLE_TXSIDE  B100_REG_ATR_BASE + 2
+#define B100_REG_ATR_INTX_RXSIDE  B100_REG_ATR_BASE + 4
+#define B100_REG_ATR_INTX_TXSIDE  B100_REG_ATR_BASE + 6
+#define	B100_REG_ATR_INRX_RXSIDE  B100_REG_ATR_BASE + 8
+#define	B100_REG_ATR_INRX_TXSIDE  B100_REG_ATR_BASE + 10
+#define	B100_REG_ATR_FULL_RXSIDE  B100_REG_ATR_BASE + 12
+#define	B100_REG_ATR_FULL_TXSIDE  B100_REG_ATR_BASE + 14
+
+///////////////////////////////////////////////////
+// Slave 7 -- Readback Mux 32
+
+#define B100_REG_RB_MUX_32_BASE  B100_REG_SLAVE(7)
+
+#define B100_REG_RB_TIME_NOW_SECS   B100_REG_RB_MUX_32_BASE + 0
+#define B100_REG_RB_TIME_NOW_TICKS  B100_REG_RB_MUX_32_BASE + 4
+#define B100_REG_RB_TIME_PPS_SECS   B100_REG_RB_MUX_32_BASE + 8
+#define B100_REG_RB_TIME_PPS_TICKS  B100_REG_RB_MUX_32_BASE + 12
+#define B100_REG_RB_MISC_TEST32     B100_REG_RB_MUX_32_BASE + 16
+
+////////////////////////////////////////////////////
+// Slaves 8 & 9 -- Settings Bus
+//
+// Output-only, no readback, 64 registers total
+//  Each register must be written 32 bits at a time
+//  First the address xxx_xx00 and then xxx_xx10
+
+#define B100_REG_SETTINGS_BASE_ADDR(n) (B100_REG_SLAVE(8) + (4*(n)))
+
+#define B100_REG_SR_MISC_TEST32        B100_REG_SETTINGS_BASE_ADDR(52)
+
+/////////////////////////////////////////////////
+// DSP RX Regs
+////////////////////////////////////////////////
+#define B100_REG_DSP_RX_ADDR(n)      (B100_REG_SETTINGS_BASE_ADDR(16) + (4*(n)))
+#define B100_REG_DSP_RX_FREQ         B100_REG_DSP_RX_ADDR(0)
+#define B100_REG_DSP_RX_SCALE_IQ     B100_REG_DSP_RX_ADDR(1)  // {scale_i,scale_q}
+#define B100_REG_DSP_RX_DECIM_RATE   B100_REG_DSP_RX_ADDR(2)  // hb and decim rate
+#define B100_REG_DSP_RX_DCOFFSET_I   B100_REG_DSP_RX_ADDR(3) // Bit 31 high sets fixed offset mode, using lower 14 bits, // otherwise it is automatic
+#define B100_REG_DSP_RX_DCOFFSET_Q   B100_REG_DSP_RX_ADDR(4) // Bit 31 high sets fixed offset mode, using lower 14 bits
+#define B100_REG_DSP_RX_MUX          B100_REG_DSP_RX_ADDR(5)
+
+///////////////////////////////////////////////////
+// VITA RX CTRL regs
+///////////////////////////////////////////////////
+// The following 3 are logically a single command register.
+// They are clocked into the underlying fifo when time_ticks is written.
+#define B100_REG_CTRL_RX_ADDR(n)           (B100_REG_SETTINGS_BASE_ADDR(0) + (4*(n)))
+#define B100_REG_CTRL_RX_STREAM_CMD        B100_REG_CTRL_RX_ADDR(0) // {now, chain, num_samples(30)
+#define B100_REG_CTRL_RX_TIME_SECS         B100_REG_CTRL_RX_ADDR(1)
+#define B100_REG_CTRL_RX_TIME_TICKS        B100_REG_CTRL_RX_ADDR(2)
+#define B100_REG_CTRL_RX_CLEAR_OVERRUN     B100_REG_CTRL_RX_ADDR(3) // write anything to clear overrun
+#define B100_REG_CTRL_RX_VRT_HEADER        B100_REG_CTRL_RX_ADDR(4) // word 0 of packet.  FPGA fills in packet counter
+#define B100_REG_CTRL_RX_VRT_STREAM_ID     B100_REG_CTRL_RX_ADDR(5) // word 1 of packet.
+#define B100_REG_CTRL_RX_VRT_TRAILER       B100_REG_CTRL_RX_ADDR(6)
+#define B100_REG_CTRL_RX_NSAMPS_PER_PKT    B100_REG_CTRL_RX_ADDR(7)
+#define B100_REG_CTRL_RX_NCHANNELS         B100_REG_CTRL_RX_ADDR(8) // 1 in basic case, up to 4 for vector sources
+
+/////////////////////////////////////////////////
+// DSP TX Regs
+////////////////////////////////////////////////
+#define B100_REG_DSP_TX_ADDR(n)      (B100_REG_SETTINGS_BASE_ADDR(32) + (4*(n)))
+#define B100_REG_DSP_TX_FREQ         B100_REG_DSP_TX_ADDR(0)
+#define B100_REG_DSP_TX_SCALE_IQ     B100_REG_DSP_TX_ADDR(1) // {scale_i,scale_q}
+#define B100_REG_DSP_TX_INTERP_RATE  B100_REG_DSP_TX_ADDR(2)
+#define B100_REG_DSP_TX_UNUSED       B100_REG_DSP_TX_ADDR(3)
+#define B100_REG_DSP_TX_MUX          B100_REG_DSP_TX_ADDR(4)
+
+/////////////////////////////////////////////////
+// VITA TX CTRL regs
+////////////////////////////////////////////////
+#define B100_REG_CTRL_TX_ADDR(n)           (B100_REG_SETTINGS_BASE_ADDR(24) + (4*(n)))
+#define B100_REG_CTRL_TX_NCHANNELS         B100_REG_CTRL_TX_ADDR(0)
+#define B100_REG_CTRL_TX_CLEAR_UNDERRUN    B100_REG_CTRL_TX_ADDR(1)
+#define B100_REG_CTRL_TX_REPORT_SID        B100_REG_CTRL_TX_ADDR(2)
+#define B100_REG_CTRL_TX_POLICY            B100_REG_CTRL_TX_ADDR(3)
+
+#define B100_FLAG_CTRL_TX_POLICY_WAIT          (0x1 << 0)
+#define B100_FLAG_CTRL_TX_POLICY_NEXT_PACKET   (0x1 << 1)
+#define B100_FLAG_CTRL_TX_POLICY_NEXT_BURST    (0x1 << 2)
+
+/////////////////////////////////////////////////
+// VITA49 64 bit time (write only)
+////////////////////////////////////////////////
+  /*!
+   * \brief Time 64 flags
+   *
+   * <pre>
+   *
+   *    3                   2                   1
+   *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+   * +-----------------------------------------------------------+-+-+
+   * |                                                           |S|P|
+   * +-----------------------------------------------------------+-+-+
+   *
+   * P - PPS edge selection (0=negedge, 1=posedge, default=0)
+   * S - Source (0=sma, 1=mimo, 0=default)
+   *
+   * </pre>
+   */
+#define B100_REG_TIME64_ADDR(n)     (B100_REG_SETTINGS_BASE_ADDR(40) + (4*(n)))
+#define B100_REG_TIME64_SECS  B100_REG_TIME64_ADDR(0)  // value to set absolute secs to on next PPS
+#define B100_REG_TIME64_TICKS B100_REG_TIME64_ADDR(1)  // value to set absolute ticks to on next PPS
+#define B100_REG_TIME64_FLAGS B100_REG_TIME64_ADDR(2)  // flags - see chart above
+#define B100_REG_TIME64_IMM   B100_REG_TIME64_ADDR(3)  // set immediate (0=latch on next pps, 1=latch immediate, default=0)
+#define B100_REG_TIME64_TPS   B100_REG_TIME64_ADDR(4)  // clock ticks per second (counter rollover)
+
+//pps flags (see above)
+#define B100_FLAG_TIME64_PPS_NEGEDGE (0 << 0)
+#define B100_FLAG_TIME64_PPS_POSEDGE (1 << 0)
+#define B100_FLAG_TIME64_PPS_SMA     (0 << 1)
+#define B100_FLAG_TIME64_PPS_MIMO    (1 << 1)
+
+#define B100_FLAG_TIME64_LATCH_NOW 1
+#define B100_FLAG_TIME64_LATCH_NEXT_PPS 0
+
+#define B100_REG_CLEAR_RX_FIFO     B100_REG_SETTINGS_BASE_ADDR(48)
+#define B100_REG_CLEAR_TX_FIFO     B100_REG_SETTINGS_BASE_ADDR(49)
+
+#define B100_REG_GLOBAL_RESET      B100_REG_SETTINGS_BASE_ADDR(50)
+#define B100_REG_TEST32            B100_REG_SETTINGS_BASE_ADDR(52)
+
+#endif
+
diff --git a/host/lib/usrp/b100/clock_ctrl.cpp b/host/lib/usrp/b100/clock_ctrl.cpp
new file mode 100644
index 000000000..e138242d1
--- /dev/null
+++ b/host/lib/usrp/b100/clock_ctrl.cpp
@@ -0,0 +1,525 @@
+//
+// Copyright 2010-2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "clock_ctrl.hpp"
+#include "ad9522_regs.hpp"
+#include <uhd/utils/log.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/exception.hpp>
+#include <uhd/utils/assert_has.hpp>
+#include <uhd/utils/safe_call.hpp>
+#include <boost/cstdint.hpp>
+#include "b100_regs.hpp" //spi slave constants
+#include <boost/assign/list_of.hpp>
+#include <boost/foreach.hpp>
+#include <boost/format.hpp>
+#include <boost/thread/thread.hpp>
+#include <boost/math/common_factor_rt.hpp> //gcd
+#include <algorithm>
+#include <utility>
+
+using namespace uhd;
+
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+static const bool ENABLE_THE_TEST_OUT = true;
+static const double REFERENCE_INPUT_RATE = 10e6;
+
+/***********************************************************************
+ * Helpers
+ **********************************************************************/
+template <typename div_type, typename bypass_type> static void set_clock_divider(
+    size_t divider, div_type &low, div_type &high, bypass_type &bypass
+){
+    high = divider/2 - 1;
+    low = divider - high - 2;
+    bypass = (divider == 1)? 1 : 0;
+}
+
+/***********************************************************************
+ * Clock rate calculation stuff:
+ *   Using the internal VCO between 1400 and 1800 MHz
+ **********************************************************************/
+struct clock_settings_type{
+    size_t ref_clock_doubler, r_counter, a_counter, b_counter, prescaler, vco_divider, chan_divider;
+    size_t get_n_counter(void) const{return prescaler * b_counter + a_counter;}
+    double get_ref_rate(void) const{return REFERENCE_INPUT_RATE * ref_clock_doubler;}
+    double get_vco_rate(void) const{return get_ref_rate()/r_counter * get_n_counter();}
+    double get_chan_rate(void) const{return get_vco_rate()/vco_divider;}
+    double get_out_rate(void) const{return get_chan_rate()/chan_divider;}
+    std::string to_pp_string(void) const{
+        return str(boost::format(
+            "  r_counter: %d\n"
+            "  a_counter: %d\n"
+            "  b_counter: %d\n"
+            "  prescaler: %d\n"
+            "  vco_divider: %d\n"
+            "  chan_divider: %d\n"
+            "  vco_rate: %fMHz\n"
+            "  chan_rate: %fMHz\n"
+            "  out_rate: %fMHz\n"
+            )
+            % r_counter
+            % a_counter
+            % b_counter
+            % prescaler
+            % vco_divider
+            % chan_divider
+            % (get_vco_rate()/1e6)
+            % (get_chan_rate()/1e6)
+            % (get_out_rate()/1e6)
+        );
+    }
+};
+
+//! gives the greatest divisor of num between 1 and max inclusive
+template<typename T> static inline T greatest_divisor(T num, T max){
+    for (T i = max; i > 1; i--) if (num%i == 0) return i; return 1;
+}
+
+//! gives the least divisor of num between min and num exclusive
+template<typename T> static inline T least_divisor(T num, T min){
+    for (T i = min; i < num; i++) if (num%i == 0) return i; return 1;
+}
+
+static clock_settings_type get_clock_settings(double rate){
+    clock_settings_type cs;
+    cs.ref_clock_doubler = 2; //always doubling
+    cs.prescaler = 8; //set to 8 when input is under 2400 MHz
+
+    //basic formulas used below:
+    //out_rate*X = ref_rate*Y
+    //X = i*ref_rate/gcd
+    //Y = i*out_rate/gcd
+    //X = chan_div * vco_div * R
+    //Y = P*B + A
+
+    const boost::uint64_t out_rate = boost::uint64_t(rate);
+    const boost::uint64_t ref_rate = boost::uint64_t(cs.get_ref_rate());
+    const size_t gcd = size_t(boost::math::gcd(ref_rate, out_rate));
+
+    for (size_t i = 1; i <= 100; i++){
+        const size_t X = i*ref_rate/gcd;
+        const size_t Y = i*out_rate/gcd;
+
+        //determine A and B (P is fixed)
+        cs.b_counter = Y/cs.prescaler;
+        cs.a_counter = Y - cs.b_counter*cs.prescaler;
+
+        static const double vco_bound_pad = 100e6;
+        for ( //calculate an r divider that fits into the bounds of the vco
+            cs.r_counter  = size_t(cs.get_n_counter()*cs.get_ref_rate()/(1800e6 - vco_bound_pad));
+            cs.r_counter <= size_t(cs.get_n_counter()*cs.get_ref_rate()/(1400e6 + vco_bound_pad))
+            and cs.r_counter > 0; cs.r_counter++
+        ){
+
+            //determine chan_div and vco_div
+            //and fill in that order of preference
+            cs.chan_divider = greatest_divisor<size_t>(X/cs.r_counter, 32);
+            cs.vco_divider = greatest_divisor<size_t>(X/cs.chan_divider/cs.r_counter, 6);
+
+            //avoid a vco divider of 1 (if possible)
+            if (cs.vco_divider == 1){
+                cs.vco_divider = least_divisor<size_t>(cs.chan_divider, 2);
+                cs.chan_divider /= cs.vco_divider;
+            }
+
+            UHD_LOGV(always)
+                << "gcd " << gcd << std::endl
+                << "X " << X << std::endl
+                << "Y " << Y << std::endl
+                << cs.to_pp_string() << std::endl
+            ;
+
+            //filter limits on the counters
+            if (cs.vco_divider == 1) continue;
+            if (cs.r_counter >= (1<<14)) continue;
+            if (cs.b_counter == 2) continue;
+            if (cs.b_counter == 1 and cs.a_counter != 0) continue;
+            if (cs.b_counter >= (1<<13)) continue;
+            if (cs.a_counter >= (1<<6)) continue;
+
+            UHD_MSG(status) << "USRP-B100 clock control: " << i << std::endl << cs.to_pp_string() << std::endl;
+            return cs;
+        }
+    }
+
+    throw uhd::runtime_error(str(boost::format(
+        "USRP-B100 clock control: could not calculate settings for clock rate %fMHz"
+    ) % (rate/1e6)));
+}
+
+/***********************************************************************
+ * Clock Control Implementation
+ **********************************************************************/
+class b100_clock_ctrl_impl : public b100_clock_ctrl{
+public:
+    b100_clock_ctrl_impl(b100_iface::sptr iface, double master_clock_rate){
+        _iface = iface;
+        _chan_rate = 0.0;
+        _out_rate = 0.0;
+
+        //init the clock gen registers
+        _ad9522_regs.sdo_active = ad9522_regs_t::SDO_ACTIVE_SDO_SDIO;
+        _ad9522_regs.enb_stat_eeprom_at_stat_pin = 0; //use status pin
+        _ad9522_regs.status_pin_control = 0x1; //n divider
+        _ad9522_regs.ld_pin_control = 0x00; //dld
+        _ad9522_regs.refmon_pin_control = 0x12; //show ref2
+        _ad9522_regs.lock_detect_counter = ad9522_regs_t::LOCK_DETECT_COUNTER_16CYC;
+
+        this->use_internal_ref();
+
+        this->set_fpga_clock_rate(master_clock_rate); //initialize to something
+
+        this->enable_fpga_clock(true);
+        this->enable_test_clock(ENABLE_THE_TEST_OUT);
+        this->enable_rx_dboard_clock(false);
+        this->enable_tx_dboard_clock(false);
+    }
+
+    ~b100_clock_ctrl_impl(void){
+        UHD_SAFE_CALL(
+            this->enable_test_clock(ENABLE_THE_TEST_OUT);
+            this->enable_rx_dboard_clock(false);
+            this->enable_tx_dboard_clock(false);
+            //this->enable_fpga_clock(false); //FIXME
+        )
+    }
+
+    /***********************************************************************
+     * Clock rate control:
+     *  - set clock rate w/ internal VCO
+     *  - set clock rate w/ external VCXO
+     **********************************************************************/
+    void set_clock_settings_with_internal_vco(double rate){
+        const clock_settings_type cs = get_clock_settings(rate);
+
+        //set the rates to private variables so the implementation knows!
+        _chan_rate = cs.get_chan_rate();
+        _out_rate = cs.get_out_rate();
+
+        _ad9522_regs.enable_clock_doubler = (cs.ref_clock_doubler == 2)? 1 : 0;
+
+        _ad9522_regs.set_r_counter(cs.r_counter);
+        _ad9522_regs.a_counter = cs.a_counter;
+        _ad9522_regs.set_b_counter(cs.b_counter);
+        UHD_ASSERT_THROW(cs.prescaler == 8); //assumes this below:
+        _ad9522_regs.prescaler_p = ad9522_regs_t::PRESCALER_P_DIV8_9;
+
+        _ad9522_regs.pll_power_down = ad9522_regs_t::PLL_POWER_DOWN_NORMAL;
+        _ad9522_regs.cp_current = ad9522_regs_t::CP_CURRENT_1_2MA;
+
+        _ad9522_regs.bypass_vco_divider = 0;
+        switch(cs.vco_divider){
+        case 1: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV1; break;
+        case 2: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV2; break;
+        case 3: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV3; break;
+        case 4: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV4; break;
+        case 5: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV5; break;
+        case 6: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV6; break;
+        }
+        _ad9522_regs.select_vco_or_clock = ad9522_regs_t::SELECT_VCO_OR_CLOCK_VCO;
+
+        //setup fpga master clock
+        _ad9522_regs.out0_format = ad9522_regs_t::OUT0_FORMAT_LVDS;
+        set_clock_divider(cs.chan_divider,
+            _ad9522_regs.divider0_low_cycles,
+            _ad9522_regs.divider0_high_cycles,
+            _ad9522_regs.divider0_bypass
+        );
+
+        //setup codec clock
+        _ad9522_regs.out3_format = ad9522_regs_t::OUT3_FORMAT_LVDS;
+        set_clock_divider(cs.chan_divider,
+            _ad9522_regs.divider1_low_cycles,
+            _ad9522_regs.divider1_high_cycles,
+            _ad9522_regs.divider1_bypass
+        );
+
+        this->send_all_regs();
+        calibrate_now();
+    }
+
+    void set_clock_settings_with_external_vcxo(double rate){
+        //set the rates to private variables so the implementation knows!
+        _chan_rate = rate;
+        _out_rate = rate;
+
+        _ad9522_regs.enable_clock_doubler = 1; //doubler always on
+        const double ref_rate = REFERENCE_INPUT_RATE*2;
+
+        //bypass prescaler such that N = B
+        long gcd = boost::math::gcd(long(ref_rate), long(rate));
+        _ad9522_regs.set_r_counter(int(ref_rate/gcd));
+        _ad9522_regs.a_counter = 0;
+        _ad9522_regs.set_b_counter(int(rate/gcd));
+        _ad9522_regs.prescaler_p = ad9522_regs_t::PRESCALER_P_DIV1;
+
+        //setup external vcxo
+        _ad9522_regs.pll_power_down = ad9522_regs_t::PLL_POWER_DOWN_NORMAL;
+        _ad9522_regs.cp_current = ad9522_regs_t::CP_CURRENT_1_2MA;
+        _ad9522_regs.bypass_vco_divider = 1;
+        _ad9522_regs.select_vco_or_clock = ad9522_regs_t::SELECT_VCO_OR_CLOCK_EXTERNAL;
+
+        //setup fpga master clock
+        _ad9522_regs.out0_format = ad9522_regs_t::OUT0_FORMAT_LVDS;
+        _ad9522_regs.divider0_bypass = 1;
+
+        //setup codec clock
+        _ad9522_regs.out3_format = ad9522_regs_t::OUT3_FORMAT_LVDS;
+        _ad9522_regs.divider1_bypass = 1;
+
+        this->send_all_regs();
+    }
+
+    void set_fpga_clock_rate(double rate){
+        if (_out_rate == rate) return;
+        if (rate == 61.44e6) set_clock_settings_with_external_vcxo(rate);
+        else                 set_clock_settings_with_internal_vco(rate);
+        //clock rate changed! update dboard clocks and FPGA ticks per second
+        set_rx_dboard_clock_rate(rate);
+        set_tx_dboard_clock_rate(rate);
+        _iface->poke32(B100_REG_TIME64_TPS, boost::uint32_t(get_fpga_clock_rate()));
+    }
+
+    double get_fpga_clock_rate(void){
+        return this->_out_rate;
+    }
+
+    /***********************************************************************
+     * FPGA clock enable
+     **********************************************************************/
+    void enable_fpga_clock(bool enb){
+        _ad9522_regs.out0_format = ad9522_regs_t::OUT0_FORMAT_LVDS;
+        _ad9522_regs.out0_lvds_power_down = !enb;
+        this->send_reg(0x0F0);
+        this->latch_regs();
+    }
+
+    /***********************************************************************
+     * Special test clock output
+     **********************************************************************/
+    void enable_test_clock(bool enb){
+        //setup test clock (same divider as codec clock)
+        _ad9522_regs.out4_format = ad9522_regs_t::OUT4_FORMAT_CMOS;
+        _ad9522_regs.out4_cmos_configuration = (enb)?
+            ad9522_regs_t::OUT4_CMOS_CONFIGURATION_A_ON :
+            ad9522_regs_t::OUT4_CMOS_CONFIGURATION_OFF;
+        this->send_reg(0x0F4);
+        this->latch_regs();
+    }
+
+    /***********************************************************************
+     * RX Dboard Clock Control (output 9, divider 3)
+     **********************************************************************/
+    void enable_rx_dboard_clock(bool enb){
+        _ad9522_regs.out9_format = ad9522_regs_t::OUT9_FORMAT_CMOS;
+        _ad9522_regs.out9_cmos_configuration = (enb)?
+            ad9522_regs_t::OUT9_CMOS_CONFIGURATION_B_ON :
+            ad9522_regs_t::OUT9_CMOS_CONFIGURATION_OFF;
+        this->send_reg(0x0F9);
+        this->latch_regs();
+    }
+
+    std::vector<double> get_rx_dboard_clock_rates(void){
+        std::vector<double> rates;
+        for(size_t div = 1; div <= 16+16; div++)
+            rates.push_back(this->_chan_rate/div);
+        return rates;
+    }
+
+    void set_rx_dboard_clock_rate(double rate){
+        assert_has(get_rx_dboard_clock_rates(), rate, "rx dboard clock rate");
+        _rx_clock_rate = rate;
+        size_t divider = size_t(this->_chan_rate/rate);
+        //set the divider registers
+        set_clock_divider(divider,
+            _ad9522_regs.divider3_low_cycles,
+            _ad9522_regs.divider3_high_cycles,
+            _ad9522_regs.divider3_bypass
+        );
+        this->send_reg(0x199);
+        this->send_reg(0x19a);
+        this->soft_sync();
+    }
+
+    double get_rx_clock_rate(void){
+        return _rx_clock_rate;
+    }
+
+    /***********************************************************************
+     * TX Dboard Clock Control (output 6, divider 2)
+     **********************************************************************/
+    void enable_tx_dboard_clock(bool enb){
+        _ad9522_regs.out6_format = ad9522_regs_t::OUT6_FORMAT_CMOS;
+        _ad9522_regs.out6_cmos_configuration = (enb)?
+            ad9522_regs_t::OUT6_CMOS_CONFIGURATION_B_ON :
+            ad9522_regs_t::OUT6_CMOS_CONFIGURATION_OFF;
+        this->send_reg(0x0F6);
+        this->latch_regs();
+    }
+
+    std::vector<double> get_tx_dboard_clock_rates(void){
+        return get_rx_dboard_clock_rates(); //same master clock, same dividers...
+    }
+
+    void set_tx_dboard_clock_rate(double rate){
+        assert_has(get_tx_dboard_clock_rates(), rate, "tx dboard clock rate");
+        _tx_clock_rate = rate;
+        size_t divider = size_t(this->_chan_rate/rate);
+        //set the divider registers
+        set_clock_divider(divider,
+            _ad9522_regs.divider2_low_cycles,
+            _ad9522_regs.divider2_high_cycles,
+            _ad9522_regs.divider2_bypass
+        );
+        this->send_reg(0x196);
+        this->send_reg(0x197);
+        this->soft_sync();
+    }
+
+    double get_tx_clock_rate(void){
+        return _tx_clock_rate;
+    }
+
+    /***********************************************************************
+     * Clock reference control
+     **********************************************************************/
+    void use_internal_ref(void) {
+        _ad9522_regs.enable_ref2 = 1;
+        _ad9522_regs.enable_ref1 = 0;
+        _ad9522_regs.select_ref = ad9522_regs_t::SELECT_REF_REF2;
+        _ad9522_regs.enb_auto_ref_switchover = ad9522_regs_t::ENB_AUTO_REF_SWITCHOVER_MANUAL;
+        this->send_reg(0x01C);
+        this->latch_regs();
+    }
+
+    void use_external_ref(void) {
+        _ad9522_regs.enable_ref2 = 0;
+        _ad9522_regs.enable_ref1 = 1;
+        _ad9522_regs.select_ref = ad9522_regs_t::SELECT_REF_REF1;
+        _ad9522_regs.enb_auto_ref_switchover = ad9522_regs_t::ENB_AUTO_REF_SWITCHOVER_MANUAL;
+        this->send_reg(0x01C);
+        this->latch_regs();
+    }
+
+    void use_auto_ref(void) {
+        _ad9522_regs.enable_ref2 = 1;
+        _ad9522_regs.enable_ref1 = 1;
+        _ad9522_regs.select_ref = ad9522_regs_t::SELECT_REF_REF1;
+        _ad9522_regs.enb_auto_ref_switchover = ad9522_regs_t::ENB_AUTO_REF_SWITCHOVER_AUTO;
+        this->send_reg(0x01C);
+        this->latch_regs();
+    }
+
+private:
+    b100_iface::sptr _iface;
+    ad9522_regs_t _ad9522_regs;
+    double _out_rate; //rate at the fpga and codec
+    double _chan_rate; //rate before final dividers
+    double _rx_clock_rate, _tx_clock_rate;
+
+    void latch_regs(void){
+        _ad9522_regs.io_update = 1;
+        this->send_reg(0x232);
+    }
+
+    void send_reg(boost::uint16_t addr){
+        boost::uint32_t reg = _ad9522_regs.get_write_reg(addr);
+        UHD_LOGV(often) << "clock control write reg: " << std::hex << reg << std::endl;
+        byte_vector_t buf;
+        buf.push_back(boost::uint8_t(reg >> 16));
+        buf.push_back(boost::uint8_t(reg >> 8));
+        buf.push_back(boost::uint8_t(reg & 0xff));
+
+        _iface->get_fx2_i2c_iface().write_i2c(0x5C, buf);
+    }
+
+    boost::uint8_t read_reg(boost::uint16_t addr){
+        byte_vector_t buf;
+        buf.push_back(boost::uint8_t(addr >> 8));
+        buf.push_back(boost::uint8_t(addr & 0xff));
+        _iface->get_fx2_i2c_iface().write_i2c(0x5C, buf);
+
+        buf = _iface->get_fx2_i2c_iface().read_i2c(0x5C, 1);
+
+        return boost::uint32_t(buf[0] & 0xFF);
+    }
+
+    void calibrate_now(void){
+        //vco calibration routine:
+        _ad9522_regs.vco_calibration_now = 0;
+        this->send_reg(0x18);
+        this->latch_regs();
+        _ad9522_regs.vco_calibration_now = 1;
+        this->send_reg(0x18);
+        this->latch_regs();
+        //wait for calibration done:
+        static const boost::uint8_t addr = 0x01F;
+        for (size_t ms10 = 0; ms10 < 100; ms10++){
+            boost::this_thread::sleep(boost::posix_time::milliseconds(10));
+            boost::uint32_t reg = read_reg(addr);
+            _ad9522_regs.set_reg(addr, reg);
+            if (_ad9522_regs.vco_calibration_finished) goto wait_for_ld;
+        }
+        UHD_MSG(error) << "USRP-B100 clock control: VCO calibration timeout" << std::endl;
+        wait_for_ld:
+        //wait for digital lock detect:
+        for (size_t ms10 = 0; ms10 < 100; ms10++){
+            boost::this_thread::sleep(boost::posix_time::milliseconds(10));
+            boost::uint32_t reg = read_reg(addr);
+            _ad9522_regs.set_reg(addr, reg);
+            if (_ad9522_regs.digital_lock_detect) return;
+        }
+        UHD_MSG(error) << "USRP-B100 clock control: lock detection timeout" << std::endl;
+    }
+
+    void soft_sync(void){
+        _ad9522_regs.soft_sync = 1;
+        this->send_reg(0x230);
+        this->latch_regs();
+        _ad9522_regs.soft_sync = 0;
+        this->send_reg(0x230);
+        this->latch_regs();
+    }
+
+    void send_all_regs(void){
+        //setup a list of register ranges to write
+        typedef std::pair<boost::uint16_t, boost::uint16_t> range_t;
+        static const std::vector<range_t> ranges = boost::assign::list_of
+            (range_t(0x000, 0x000)) (range_t(0x010, 0x01F))
+            (range_t(0x0F0, 0x0FD)) (range_t(0x190, 0x19B))
+            (range_t(0x1E0, 0x1E1)) (range_t(0x230, 0x230))
+        ;
+
+        //write initial register values and latch/update
+        BOOST_FOREACH(const range_t &range, ranges){
+            for(boost::uint16_t addr = range.first; addr <= range.second; addr++){
+                this->send_reg(addr);
+            }
+        }
+        this->latch_regs();
+    }
+};
+
+/***********************************************************************
+ * Clock Control Make
+ **********************************************************************/
+b100_clock_ctrl::sptr b100_clock_ctrl::make(b100_iface::sptr iface, double master_clock_rate){
+    return sptr(new b100_clock_ctrl_impl(iface, master_clock_rate));
+}
diff --git a/host/lib/usrp/b100/clock_ctrl.hpp b/host/lib/usrp/b100/clock_ctrl.hpp
new file mode 100644
index 000000000..2a2e74024
--- /dev/null
+++ b/host/lib/usrp/b100/clock_ctrl.hpp
@@ -0,0 +1,118 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_B100_CLOCK_CTRL_HPP
+#define INCLUDED_B100_CLOCK_CTRL_HPP
+
+#include "b100_iface.hpp"
+#include <boost/shared_ptr.hpp>
+#include <boost/utility.hpp>
+#include <vector>
+
+/*!
+ * The usrp-e clock control:
+ * - Setup system clocks.
+ * - Disable/enable clock lines.
+ */
+class b100_clock_ctrl : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<b100_clock_ctrl> sptr;
+
+    /*!
+     * Make a new clock control object.
+     * \param iface the b100 iface object
+     * \param master_clock_rate the master FPGA/sample clock rate
+     * \return the clock control object
+     */
+    static sptr make(b100_iface::sptr iface, double master_clock_rate);
+
+    /*!
+     * Set the rate of the fpga clock line.
+     * Throws if rate is not valid.
+     * \param rate the new rate in Hz
+     */
+    virtual void set_fpga_clock_rate(double rate) = 0;
+
+    /*!
+     * Get the rate of the fpga clock line.
+     * \return the fpga clock rate in Hz
+     */
+    virtual double get_fpga_clock_rate(void) = 0;
+
+    /*!
+     * Get the possible rates of the rx dboard clock.
+     * \return a vector of clock rates in Hz
+     */
+    virtual std::vector<double> get_rx_dboard_clock_rates(void) = 0;
+
+    /*!
+     * Get the possible rates of the tx dboard clock.
+     * \return a vector of clock rates in Hz
+     */
+    virtual std::vector<double> get_tx_dboard_clock_rates(void) = 0;
+
+    /*!
+     * Set the rx dboard clock rate to a possible rate.
+     * \param rate the new clock rate in Hz
+     * \throw exception when rate cannot be achieved
+     */
+    virtual void set_rx_dboard_clock_rate(double rate) = 0;
+
+    /*!
+     * Set the tx dboard clock rate to a possible rate.
+     * \param rate the new clock rate in Hz
+     * \throw exception when rate cannot be achieved
+     */
+    virtual void set_tx_dboard_clock_rate(double rate) = 0;
+    
+    /*!
+     * Enable/disable the FPGA clock.
+     * \param enb true to enable
+     */
+    
+    virtual void enable_fpga_clock(bool enb) = 0;
+
+    /*!
+     * Enable/disable the rx dboard clock.
+     * \param enb true to enable
+     */
+    virtual void enable_rx_dboard_clock(bool enb) = 0;
+
+    /*!
+     * Enable/disable the tx dboard clock.
+     * \param enb true to enable
+     */
+    virtual void enable_tx_dboard_clock(bool enb) = 0;
+    
+    /*!
+     * Use the internal TCXO reference
+     */
+    virtual void use_internal_ref(void) = 0;
+    
+    /*!
+     * Use the external SMA reference
+     */
+    virtual void use_external_ref(void) = 0;
+    
+    /*!
+     * Use external if available, internal otherwise
+     */
+    virtual void use_auto_ref(void) = 0;
+
+};
+
+#endif /* INCLUDED_B100_CLOCK_CTRL_HPP */
diff --git a/host/lib/usrp/b100/codec_ctrl.cpp b/host/lib/usrp/b100/codec_ctrl.cpp
new file mode 100644
index 000000000..4d118b68b
--- /dev/null
+++ b/host/lib/usrp/b100/codec_ctrl.cpp
@@ -0,0 +1,283 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "codec_ctrl.hpp"
+#include "ad9862_regs.hpp"
+#include <uhd/types/dict.hpp>
+#include <uhd/exception.hpp>
+#include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/log.hpp>
+#include <uhd/utils/safe_call.hpp>
+#include <boost/cstdint.hpp>
+#include <boost/tuple/tuple.hpp>
+#include <boost/math/special_functions/round.hpp>
+#include "b100_regs.hpp" //spi slave constants
+#include <boost/assign/list_of.hpp>
+
+using namespace uhd;
+
+const gain_range_t b100_codec_ctrl::tx_pga_gain_range(-20, 0, double(0.1));
+const gain_range_t b100_codec_ctrl::rx_pga_gain_range(0, 20, 1);
+
+/***********************************************************************
+ * Codec Control Implementation
+ **********************************************************************/
+class b100_codec_ctrl_impl : public b100_codec_ctrl{
+public:
+    //structors
+    b100_codec_ctrl_impl(b100_iface::sptr iface);
+    ~b100_codec_ctrl_impl(void);
+
+    //aux adc and dac control
+    double read_aux_adc(aux_adc_t which);
+    void write_aux_dac(aux_dac_t which, double volts);
+
+    //pga gain control
+    void set_tx_pga_gain(double);
+    double get_tx_pga_gain(void);
+    void set_rx_pga_gain(double, char);
+    double get_rx_pga_gain(char);
+
+private:
+    b100_iface::sptr _iface;
+    ad9862_regs_t _ad9862_regs;
+    void send_reg(boost::uint8_t addr);
+    void recv_reg(boost::uint8_t addr);
+};
+
+/***********************************************************************
+ * Codec Control Structors
+ **********************************************************************/
+b100_codec_ctrl_impl::b100_codec_ctrl_impl(b100_iface::sptr iface){
+    _iface = iface;
+
+    //soft reset
+    _ad9862_regs.soft_reset = 1;
+    this->send_reg(0);
+
+    //initialize the codec register settings
+    _ad9862_regs.sdio_bidir = ad9862_regs_t::SDIO_BIDIR_SDIO_SDO;
+    _ad9862_regs.lsb_first = ad9862_regs_t::LSB_FIRST_MSB;
+    _ad9862_regs.soft_reset = 0;
+
+    //setup rx side of codec
+    _ad9862_regs.byp_buffer_a = 1;
+    _ad9862_regs.byp_buffer_b = 1;
+    _ad9862_regs.buffer_a_pd = 1;
+    _ad9862_regs.buffer_b_pd = 1;
+    _ad9862_regs.mux_out = ad9862_regs_t::MUX_OUT_RX_MUX_MODE; //B100 uses interleaved RX->FPGA
+    _ad9862_regs.rx_pga_a = 0;//0x1f;  //TODO bring under api control
+    _ad9862_regs.rx_pga_b = 0;//0x1f;  //TODO bring under api control
+    _ad9862_regs.rx_twos_comp = 1;
+    _ad9862_regs.rx_hilbert = ad9862_regs_t::RX_HILBERT_DIS;
+
+    //setup tx side of codec
+    _ad9862_regs.two_data_paths = ad9862_regs_t::TWO_DATA_PATHS_BOTH;
+    _ad9862_regs.interleaved = ad9862_regs_t::INTERLEAVED_INTERLEAVED;
+    _ad9862_regs.tx_retime = ad9862_regs_t::TX_RETIME_CLKOUT2;
+    _ad9862_regs.tx_pga_gain = 199; //TODO bring under api control
+    _ad9862_regs.tx_hilbert = ad9862_regs_t::TX_HILBERT_DIS;
+    _ad9862_regs.interp = ad9862_regs_t::INTERP_2;
+    _ad9862_regs.tx_twos_comp = 1;
+    _ad9862_regs.fine_mode = ad9862_regs_t::FINE_MODE_BYPASS;
+    _ad9862_regs.coarse_mod = ad9862_regs_t::COARSE_MOD_BYPASS;
+    _ad9862_regs.dac_a_coarse_gain = 0x3;
+    _ad9862_regs.dac_b_coarse_gain = 0x3;
+    _ad9862_regs.edges = ad9862_regs_t::EDGES_NORMAL;
+
+    //setup the dll
+    _ad9862_regs.input_clk_ctrl = ad9862_regs_t::INPUT_CLK_CTRL_EXTERNAL;
+    _ad9862_regs.dll_mult = ad9862_regs_t::DLL_MULT_2;
+    _ad9862_regs.dll_mode = ad9862_regs_t::DLL_MODE_FAST;
+
+    //write the register settings to the codec
+    for (uint8_t addr = 0; addr <= 25; addr++){
+        this->send_reg(addr);
+    }
+
+    //always start conversions for aux ADC
+    _ad9862_regs.start_a = 1;
+    _ad9862_regs.start_b = 1;
+
+    //aux adc clock
+    _ad9862_regs.clk_4 = ad9862_regs_t::CLK_4_1_4;
+    this->send_reg(34);
+}
+
+b100_codec_ctrl_impl::~b100_codec_ctrl_impl(void){
+    UHD_SAFE_CALL(
+        //set aux dacs to zero
+        this->write_aux_dac(AUX_DAC_A, 0);
+        this->write_aux_dac(AUX_DAC_B, 0);
+        this->write_aux_dac(AUX_DAC_C, 0);
+        this->write_aux_dac(AUX_DAC_D, 0);
+
+        //power down
+        _ad9862_regs.all_rx_pd = 1;
+        this->send_reg(1);
+        _ad9862_regs.tx_digital_pd = 1;
+        _ad9862_regs.tx_analog_pd = ad9862_regs_t::TX_ANALOG_PD_BOTH;
+        this->send_reg(8);
+    )
+}
+
+/***********************************************************************
+ * Codec Control Gain Control Methods
+ **********************************************************************/
+static const int mtpgw = 255; //maximum tx pga gain word
+
+void b100_codec_ctrl_impl::set_tx_pga_gain(double gain){
+    int gain_word = int(mtpgw*(gain - tx_pga_gain_range.start())/(tx_pga_gain_range.stop() - tx_pga_gain_range.start()));
+    _ad9862_regs.tx_pga_gain = uhd::clip(gain_word, 0, mtpgw);
+    this->send_reg(16);
+}
+
+double b100_codec_ctrl_impl::get_tx_pga_gain(void){
+    return (_ad9862_regs.tx_pga_gain*(tx_pga_gain_range.stop() - tx_pga_gain_range.start())/mtpgw) + tx_pga_gain_range.start();
+}
+
+static const int mrpgw = 0x14; //maximum rx pga gain word
+
+void b100_codec_ctrl_impl::set_rx_pga_gain(double gain, char which){
+    int gain_word = int(mrpgw*(gain - rx_pga_gain_range.start())/(rx_pga_gain_range.stop() - rx_pga_gain_range.start()));
+    gain_word = uhd::clip(gain_word, 0, mrpgw);
+    switch(which){
+    case 'A':
+        _ad9862_regs.rx_pga_a = gain_word;
+        this->send_reg(2);
+        return;
+    case 'B':
+        _ad9862_regs.rx_pga_b = gain_word;
+        this->send_reg(3);
+        return;
+    default: UHD_THROW_INVALID_CODE_PATH();
+    }
+}
+
+double b100_codec_ctrl_impl::get_rx_pga_gain(char which){
+    int gain_word;
+    switch(which){
+    case 'A': gain_word = _ad9862_regs.rx_pga_a; break;
+    case 'B': gain_word = _ad9862_regs.rx_pga_b; break;
+    default: UHD_THROW_INVALID_CODE_PATH();
+    }
+    return (gain_word*(rx_pga_gain_range.stop() - rx_pga_gain_range.start())/mrpgw) + rx_pga_gain_range.start();
+}
+
+/***********************************************************************
+ * Codec Control AUX ADC Methods
+ **********************************************************************/
+static double aux_adc_to_volts(boost::uint8_t high, boost::uint8_t low){
+    return double((boost::uint16_t(high) << 2) | low)*3.3/0x3ff;
+}
+
+double b100_codec_ctrl_impl::read_aux_adc(aux_adc_t which){
+    switch(which){
+
+    case AUX_ADC_A1:
+        _ad9862_regs.select_a = ad9862_regs_t::SELECT_A_AUX_ADC1;
+        this->send_reg(34); //start conversion and select mux
+        this->recv_reg(28); //read the value (2 bytes, 2 reads)
+        this->recv_reg(29);
+        return aux_adc_to_volts(_ad9862_regs.aux_adc_a1_9_2, _ad9862_regs.aux_adc_a1_1_0);
+    case AUX_ADC_A2:
+        _ad9862_regs.select_a = ad9862_regs_t::SELECT_A_AUX_ADC2;
+        this->send_reg(34); //start conversion and select mux
+        this->recv_reg(26); //read the value (2 bytes, 2 reads)
+        this->recv_reg(27);
+        return aux_adc_to_volts(_ad9862_regs.aux_adc_a2_9_2, _ad9862_regs.aux_adc_a2_1_0);
+
+    case AUX_ADC_B1:
+        _ad9862_regs.select_b = ad9862_regs_t::SELECT_B_AUX_ADC1;
+        this->send_reg(34); //start conversion and select mux
+        this->recv_reg(32); //read the value (2 bytes, 2 reads)
+        this->recv_reg(33);
+        return aux_adc_to_volts(_ad9862_regs.aux_adc_b1_9_2, _ad9862_regs.aux_adc_b1_1_0);
+    case AUX_ADC_B2:
+        _ad9862_regs.select_b = ad9862_regs_t::SELECT_B_AUX_ADC2;
+        this->send_reg(34); //start conversion and select mux
+        this->recv_reg(30); //read the value (2 bytes, 2 reads)
+        this->recv_reg(31);
+        return aux_adc_to_volts(_ad9862_regs.aux_adc_b2_9_2, _ad9862_regs.aux_adc_b2_1_0);
+    }
+    UHD_THROW_INVALID_CODE_PATH();
+}
+
+/***********************************************************************
+ * Codec Control AUX DAC Methods
+ **********************************************************************/
+void b100_codec_ctrl_impl::write_aux_dac(aux_dac_t which, double volts){
+    //special case for aux dac d (aka sigma delta word)
+    if (which == AUX_DAC_D){
+        boost::uint16_t dac_word = uhd::clip(boost::math::iround(volts*0xfff/3.3), 0, 0xfff);
+        _ad9862_regs.sig_delt_11_4 = boost::uint8_t(dac_word >> 4);
+        _ad9862_regs.sig_delt_3_0 = boost::uint8_t(dac_word & 0xf);
+        this->send_reg(42);
+        this->send_reg(43);
+        return;
+    }
+
+    //calculate the dac word for aux dac a, b, c
+    boost::uint8_t dac_word = uhd::clip(boost::math::iround(volts*0xff/3.3), 0, 0xff);
+
+    //setup a lookup table for the aux dac params (reg ref, reg addr)
+    typedef boost::tuple<boost::uint8_t*, boost::uint8_t> dac_params_t;
+    uhd::dict<aux_dac_t, dac_params_t> aux_dac_to_params = boost::assign::map_list_of
+        (AUX_DAC_A, dac_params_t(&_ad9862_regs.aux_dac_a, 36))
+        (AUX_DAC_B, dac_params_t(&_ad9862_regs.aux_dac_b, 37))
+        (AUX_DAC_C, dac_params_t(&_ad9862_regs.aux_dac_c, 38))
+    ;
+
+    //set the aux dac register
+    UHD_ASSERT_THROW(aux_dac_to_params.has_key(which));
+    boost::uint8_t *reg_ref, reg_addr;
+    boost::tie(reg_ref, reg_addr) = aux_dac_to_params[which];
+    *reg_ref = dac_word;
+    this->send_reg(reg_addr);
+}
+
+/***********************************************************************
+ * Codec Control SPI Methods
+ **********************************************************************/
+void b100_codec_ctrl_impl::send_reg(boost::uint8_t addr){
+    boost::uint32_t reg = _ad9862_regs.get_write_reg(addr);
+    UHD_LOGV(rarely) << "codec control write reg: " << std::hex << reg << std::endl;
+    _iface->transact_spi(
+        B100_SPI_SS_AD9862,
+        spi_config_t::EDGE_RISE,
+        reg, 16, false /*no rb*/
+    );
+}
+
+void b100_codec_ctrl_impl::recv_reg(boost::uint8_t addr){
+    boost::uint32_t reg = _ad9862_regs.get_read_reg(addr);
+    UHD_LOGV(rarely) << "codec control read reg: " << std::hex << reg << std::endl;
+    boost::uint32_t ret = _iface->transact_spi(
+        B100_SPI_SS_AD9862,
+        spi_config_t::EDGE_RISE,
+        reg, 16, true /*rb*/
+    );
+    UHD_LOGV(rarely) << "codec control read ret: " << std::hex << boost::uint16_t(ret & 0xFF) << std::endl;
+    _ad9862_regs.set_reg(addr, boost::uint8_t(ret&0xff));
+}
+
+/***********************************************************************
+ * Codec Control Make
+ **********************************************************************/
+b100_codec_ctrl::sptr b100_codec_ctrl::make(b100_iface::sptr iface){
+    return sptr(new b100_codec_ctrl_impl(iface));
+}
diff --git a/host/lib/usrp/b100/codec_ctrl.hpp b/host/lib/usrp/b100/codec_ctrl.hpp
new file mode 100644
index 000000000..1bd579190
--- /dev/null
+++ b/host/lib/usrp/b100/codec_ctrl.hpp
@@ -0,0 +1,90 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_B100_CODEC_CTRL_HPP
+#define INCLUDED_B100_CODEC_CTRL_HPP
+
+#include "b100_iface.hpp"
+#include <uhd/types/ranges.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/utility.hpp>
+
+/*!
+ * The usrp-e codec control:
+ * - Init/power down codec.
+ * - Read aux adc, write aux dac.
+ */
+class b100_codec_ctrl : boost::noncopyable{
+public:
+    typedef boost::shared_ptr<b100_codec_ctrl> sptr;
+
+    static const uhd::gain_range_t tx_pga_gain_range;
+    static const uhd::gain_range_t rx_pga_gain_range;
+
+    /*!
+     * Make a new codec control object.
+     * \param iface the usrp_e iface object
+     * \return the codec control object
+     */
+    static sptr make(b100_iface::sptr iface);
+
+    //! aux adc identifier constants
+    enum aux_adc_t{
+        AUX_ADC_A2 = 0xA2,
+        AUX_ADC_A1 = 0xA1,
+        AUX_ADC_B2 = 0xB2,
+        AUX_ADC_B1 = 0xB1
+    };
+
+    /*!
+     * Read an auxiliary adc:
+     * The internals remember which aux adc was read last.
+     * Therefore, the aux adc switch is only changed as needed.
+     * \param which which of the 4 adcs
+     * \return a value in volts
+     */
+    virtual double read_aux_adc(aux_adc_t which) = 0;
+
+    //! aux dac identifier constants
+    enum aux_dac_t{
+        AUX_DAC_A = 0xA,
+        AUX_DAC_B = 0xB,
+        AUX_DAC_C = 0xC,
+        AUX_DAC_D = 0xD //really the sigma delta output
+    };
+
+    /*!
+     * Write an auxiliary dac.
+     * \param which which of the 4 dacs
+     * \param volts the level in in volts
+     */
+    virtual void write_aux_dac(aux_dac_t which, double volts) = 0;
+
+    //! Set the TX PGA gain
+    virtual void set_tx_pga_gain(double gain) = 0;
+
+    //! Get the TX PGA gain
+    virtual double get_tx_pga_gain(void) = 0;
+
+    //! Set the RX PGA gain ('A' or 'B')
+    virtual void set_rx_pga_gain(double gain, char which) = 0;
+
+    //! Get the RX PGA gain ('A' or 'B')
+    virtual double get_rx_pga_gain(char which) = 0;
+};
+
+#endif /* INCLUDED_B100_CODEC_CTRL_HPP */
diff --git a/host/lib/usrp/b100/codec_impl.cpp b/host/lib/usrp/b100/codec_impl.cpp
new file mode 100644
index 000000000..de3ca3a66
--- /dev/null
+++ b/host/lib/usrp/b100/codec_impl.cpp
@@ -0,0 +1,149 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_impl.hpp"
+#include <uhd/exception.hpp>
+#include <uhd/usrp/codec_props.hpp>
+#include <boost/bind.hpp>
+
+using namespace uhd;
+using namespace uhd::usrp;
+
+/***********************************************************************
+ * Helper Methods
+ **********************************************************************/
+void b100_impl::codec_init(void){
+    //make proxies
+    _rx_codec_proxy = wax_obj_proxy::make(
+        boost::bind(&b100_impl::rx_codec_get, this, _1, _2),
+        boost::bind(&b100_impl::rx_codec_set, this, _1, _2)
+    );
+    _tx_codec_proxy = wax_obj_proxy::make(
+        boost::bind(&b100_impl::tx_codec_get, this, _1, _2),
+        boost::bind(&b100_impl::tx_codec_set, this, _1, _2)
+    );
+}
+
+/***********************************************************************
+ * RX Codec Properties
+ **********************************************************************/
+static const std::string ad9862_pga_gain_name = "ad9862 pga";
+
+void b100_impl::rx_codec_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<codec_prop_t>()){
+    case CODEC_PROP_NAME:
+        val = std::string("b100 adc - ad9522");
+        return;
+
+    case CODEC_PROP_OTHERS:
+        val = prop_names_t();
+        return;
+
+    case CODEC_PROP_GAIN_NAMES:
+        val = prop_names_t(1, ad9862_pga_gain_name);
+        return;
+
+    case CODEC_PROP_GAIN_RANGE:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        val = b100_codec_ctrl::rx_pga_gain_range;
+        return;
+
+    case CODEC_PROP_GAIN_I:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        val = _codec_ctrl->get_rx_pga_gain('A');
+        return;
+
+    case CODEC_PROP_GAIN_Q:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        val = _codec_ctrl->get_rx_pga_gain('B');
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+void b100_impl::rx_codec_set(const wax::obj &key_, const wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the set request conditioned on the key
+    switch(key.as<codec_prop_t>()){
+    case CODEC_PROP_GAIN_I:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        _codec_ctrl->set_rx_pga_gain(val.as<double>(), 'A');
+        return;
+
+    case CODEC_PROP_GAIN_Q:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        _codec_ctrl->set_rx_pga_gain(val.as<double>(), 'B');
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * TX Codec Properties
+ **********************************************************************/
+void b100_impl::tx_codec_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<codec_prop_t>()){
+    case CODEC_PROP_NAME:
+        val = std::string("b100 dac - ad9522");
+        return;
+
+    case CODEC_PROP_OTHERS:
+        val = prop_names_t();
+        return;
+
+    case CODEC_PROP_GAIN_NAMES:
+        val = prop_names_t(1, ad9862_pga_gain_name);
+        return;
+
+    case CODEC_PROP_GAIN_RANGE:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        val = b100_codec_ctrl::tx_pga_gain_range;
+        return;
+
+    case CODEC_PROP_GAIN_I: //only one gain for I and Q
+    case CODEC_PROP_GAIN_Q:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        val = _codec_ctrl->get_tx_pga_gain();
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+void b100_impl::tx_codec_set(const wax::obj &key_, const wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the set request conditioned on the key
+    switch(key.as<codec_prop_t>()){
+    case CODEC_PROP_GAIN_I: //only one gain for I and Q
+    case CODEC_PROP_GAIN_Q:
+        UHD_ASSERT_THROW(key.name == ad9862_pga_gain_name);
+        _codec_ctrl->set_tx_pga_gain(val.as<double>());
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
diff --git a/host/lib/usrp/b100/ctrl_packet.hpp b/host/lib/usrp/b100/ctrl_packet.hpp
new file mode 100644
index 000000000..f504fc5aa
--- /dev/null
+++ b/host/lib/usrp/b100/ctrl_packet.hpp
@@ -0,0 +1,75 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_CTRL_PACKET_HPP
+#define INCLUDED_CTRL_PACKET_HPP
+
+#include <uhd/config.hpp>
+#include <boost/cstdint.hpp>
+#include <uhd/types/serial.hpp>
+
+typedef std::vector<boost::uint16_t> ctrl_data_t;
+
+/*!
+ * Control packet operation type
+ */
+enum ctrl_pkt_op_t { 
+    CTRL_PKT_OP_WRITE = 1,
+    CTRL_PKT_OP_READ = 2,
+    CTRL_PKT_OP_READBACK = 3
+};
+
+/*!
+ * Control packet transaction length
+ */
+const size_t CTRL_PACKET_LENGTH = 32;
+const size_t CTRL_PACKET_HEADER_LENGTH = 8;
+const size_t CTRL_PACKET_DATA_LENGTH = 24; //=length-header
+
+/*!
+ * Control packet header magic value
+ */
+const boost::uint8_t CTRL_PACKET_HEADER_MAGIC = 0xAA;
+
+/*! 
+ * Callback triggers for readback operation
+ */
+//FIXME: these are not real numbers, callbacks aren't implemented yet
+const boost::uint16_t CTRL_PACKET_CALLBACK_SPI = 0x0001;
+const boost::uint16_t CTRL_PACKET_CALLBACK_I2C = 0x0002;
+//and so on
+
+/*!
+ * Metadata structure to describe a control packet
+ */
+struct UHD_API ctrl_pkt_meta_t {
+    ctrl_pkt_op_t op;
+    boost::uint8_t callbacks;
+    boost::uint8_t seq;
+    boost::uint16_t len;
+    boost::uint32_t addr;
+};
+
+/*! 
+ * Full control packet structure
+ */
+struct UHD_API ctrl_pkt_t {
+    ctrl_pkt_meta_t pkt_meta;
+    ctrl_data_t data;
+};
+
+#endif /* INCLUDED_CTRL_PACKET_HPP */
diff --git a/host/lib/usrp/b100/dboard_iface.cpp b/host/lib/usrp/b100/dboard_iface.cpp
new file mode 100644
index 000000000..ec3da6220
--- /dev/null
+++ b/host/lib/usrp/b100/dboard_iface.cpp
@@ -0,0 +1,298 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_iface.hpp"
+#include "b100_regs.hpp"
+#include "clock_ctrl.hpp"
+#include "codec_ctrl.hpp"
+#include <uhd/usrp/dboard_iface.hpp>
+#include <uhd/types/dict.hpp>
+#include <uhd/exception.hpp>
+#include <boost/assign/list_of.hpp>
+
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace boost::assign;
+
+class b100_dboard_iface : public dboard_iface{
+public:
+
+    b100_dboard_iface(
+        b100_iface::sptr iface,
+        b100_clock_ctrl::sptr clock,
+        b100_codec_ctrl::sptr codec
+    ){
+        _iface = iface;
+        _clock = clock;
+        _codec = codec;
+
+        //init the clock rate shadows
+        this->set_clock_rate(UNIT_RX, _clock->get_fpga_clock_rate());
+        this->set_clock_rate(UNIT_TX, _clock->get_fpga_clock_rate());
+
+        _iface->poke16(B100_REG_GPIO_RX_DBG, 0);
+        _iface->poke16(B100_REG_GPIO_TX_DBG, 0);
+    }
+
+    ~b100_dboard_iface(void){
+        /* NOP */
+    }
+
+    special_props_t get_special_props(void){
+        special_props_t props;
+        props.soft_clock_divider = false;
+        props.mangle_i2c_addrs = false;
+        return props;
+    }
+
+    void write_aux_dac(unit_t, aux_dac_t, double);
+    double read_aux_adc(unit_t, aux_adc_t);
+
+    void _set_pin_ctrl(unit_t, boost::uint16_t);
+    void _set_atr_reg(unit_t, atr_reg_t, boost::uint16_t);
+    void _set_gpio_ddr(unit_t, boost::uint16_t);
+    void _set_gpio_out(unit_t, boost::uint16_t);
+    void set_gpio_debug(unit_t, int);
+    boost::uint16_t read_gpio(unit_t);
+
+    void write_i2c(boost::uint8_t, const byte_vector_t &);
+    byte_vector_t read_i2c(boost::uint8_t, size_t);
+
+    void write_spi(
+        unit_t unit,
+        const spi_config_t &config,
+        boost::uint32_t data,
+        size_t num_bits
+    );
+
+    boost::uint32_t read_write_spi(
+        unit_t unit,
+        const spi_config_t &config,
+        boost::uint32_t data,
+        size_t num_bits
+    );
+
+    void set_clock_rate(unit_t, double);
+    std::vector<double> get_clock_rates(unit_t);
+    double get_clock_rate(unit_t);
+    void set_clock_enabled(unit_t, bool);
+    double get_codec_rate(unit_t);
+
+private:
+    b100_iface::sptr _iface;
+    b100_clock_ctrl::sptr _clock;
+    b100_codec_ctrl::sptr _codec;
+    uhd::dict<unit_t, double> _clock_rates;
+};
+
+/***********************************************************************
+ * Make Function
+ **********************************************************************/
+dboard_iface::sptr make_b100_dboard_iface(
+    b100_iface::sptr iface,
+    b100_clock_ctrl::sptr clock,
+    b100_codec_ctrl::sptr codec
+){
+    return dboard_iface::sptr(new b100_dboard_iface(iface, clock, codec));
+}
+
+/***********************************************************************
+ * Clock Rates
+ **********************************************************************/
+void b100_dboard_iface::set_clock_rate(unit_t unit, double rate){
+    _clock_rates[unit] = rate;
+    switch(unit){
+    case UNIT_RX: return _clock->set_rx_dboard_clock_rate(rate);
+    case UNIT_TX: return _clock->set_tx_dboard_clock_rate(rate);
+    }
+}
+
+std::vector<double> b100_dboard_iface::get_clock_rates(unit_t unit){
+    switch(unit){
+    case UNIT_RX: return _clock->get_rx_dboard_clock_rates();
+    case UNIT_TX: return _clock->get_tx_dboard_clock_rates();
+    default: UHD_THROW_INVALID_CODE_PATH();
+    }
+}
+
+double b100_dboard_iface::get_clock_rate(unit_t unit){
+    return _clock_rates[unit];
+}
+
+void b100_dboard_iface::set_clock_enabled(unit_t unit, bool enb){
+    switch(unit){
+    case UNIT_RX: return _clock->enable_rx_dboard_clock(enb);
+    case UNIT_TX: return _clock->enable_tx_dboard_clock(enb);
+    }
+}
+
+double b100_dboard_iface::get_codec_rate(unit_t){
+    return _clock->get_fpga_clock_rate();
+}
+
+/***********************************************************************
+ * GPIO
+ **********************************************************************/
+void b100_dboard_iface::_set_pin_ctrl(unit_t unit, boost::uint16_t value){
+    UHD_ASSERT_THROW(GPIO_SEL_ATR == 1); //make this assumption
+    switch(unit){
+    case UNIT_RX: _iface->poke16(B100_REG_GPIO_RX_SEL, value); return;
+    case UNIT_TX: _iface->poke16(B100_REG_GPIO_TX_SEL, value); return;
+    }
+}
+
+void b100_dboard_iface::_set_gpio_ddr(unit_t unit, boost::uint16_t value){
+    switch(unit){
+    case UNIT_RX: _iface->poke16(B100_REG_GPIO_RX_DDR, value); return;
+    case UNIT_TX: _iface->poke16(B100_REG_GPIO_TX_DDR, value); return;
+    }
+}
+
+void b100_dboard_iface::_set_gpio_out(unit_t unit, boost::uint16_t value){
+    switch(unit){
+    case UNIT_RX: _iface->poke16(B100_REG_GPIO_RX_IO, value); return;
+    case UNIT_TX: _iface->poke16(B100_REG_GPIO_TX_IO, value); return;
+    }
+}
+
+boost::uint16_t b100_dboard_iface::read_gpio(unit_t unit){
+    switch(unit){
+    case UNIT_RX: return _iface->peek16(B100_REG_GPIO_RX_IO);
+    case UNIT_TX: return _iface->peek16(B100_REG_GPIO_TX_IO);
+    default: UHD_THROW_INVALID_CODE_PATH();
+    }
+}
+
+void b100_dboard_iface::_set_atr_reg(unit_t unit, atr_reg_t atr, boost::uint16_t value){
+    //define mapping of unit to atr regs to register address
+    static const uhd::dict<
+        unit_t, uhd::dict<atr_reg_t, boost::uint32_t>
+    > unit_to_atr_to_addr = map_list_of
+        (UNIT_RX, map_list_of
+            (ATR_REG_IDLE,        B100_REG_ATR_IDLE_RXSIDE)
+            (ATR_REG_TX_ONLY,     B100_REG_ATR_INTX_RXSIDE)
+            (ATR_REG_RX_ONLY,     B100_REG_ATR_INRX_RXSIDE)
+            (ATR_REG_FULL_DUPLEX, B100_REG_ATR_FULL_RXSIDE)
+        )
+        (UNIT_TX, map_list_of
+            (ATR_REG_IDLE,        B100_REG_ATR_IDLE_TXSIDE)
+            (ATR_REG_TX_ONLY,     B100_REG_ATR_INTX_TXSIDE)
+            (ATR_REG_RX_ONLY,     B100_REG_ATR_INRX_TXSIDE)
+            (ATR_REG_FULL_DUPLEX, B100_REG_ATR_FULL_TXSIDE)
+        )
+    ;
+    _iface->poke16(unit_to_atr_to_addr[unit][atr], value);
+}
+
+void b100_dboard_iface::set_gpio_debug(unit_t unit, int which){
+    //set this unit to all outputs
+    this->set_gpio_ddr(unit, 0xffff);
+
+    //calculate the debug selections
+    boost::uint32_t dbg_sels = 0x0;
+    int sel = (which == 0)? GPIO_SEL_DEBUG_0 : GPIO_SEL_DEBUG_1;
+    for(size_t i = 0; i < 16; i++) dbg_sels |= sel << i;
+
+    //set the debug on and which debug selection
+    switch(unit){
+    case UNIT_RX:
+        _iface->poke16(B100_REG_GPIO_RX_DBG, 0xffff);
+        _iface->poke16(B100_REG_GPIO_RX_SEL, dbg_sels);
+        return;
+
+    case UNIT_TX:
+        _iface->poke16(B100_REG_GPIO_TX_DBG, 0xffff);
+        _iface->poke16(B100_REG_GPIO_TX_SEL, dbg_sels);
+        return;
+    }
+}
+
+/***********************************************************************
+ * SPI
+ **********************************************************************/
+/*!
+ * Static function to convert a unit type to a spi slave device number.
+ * \param unit the dboard interface unit type enum
+ * \return the slave device number
+ */
+static boost::uint32_t unit_to_otw_spi_dev(dboard_iface::unit_t unit){
+    switch(unit){
+    case dboard_iface::UNIT_TX: return B100_SPI_SS_TX_DB;
+    case dboard_iface::UNIT_RX: return B100_SPI_SS_RX_DB;
+    }
+    throw std::invalid_argument("unknown unit type");
+}
+
+void b100_dboard_iface::write_spi(
+    unit_t unit,
+    const spi_config_t &config,
+    boost::uint32_t data,
+    size_t num_bits
+){
+    _iface->transact_spi(unit_to_otw_spi_dev(unit), config, data, num_bits, false /*no rb*/);
+}
+
+boost::uint32_t b100_dboard_iface::read_write_spi(
+    unit_t unit,
+    const spi_config_t &config,
+    boost::uint32_t data,
+    size_t num_bits
+){
+    return _iface->transact_spi(unit_to_otw_spi_dev(unit), config, data, num_bits, true /*rb*/);
+}
+
+/***********************************************************************
+ * I2C
+ **********************************************************************/
+void b100_dboard_iface::write_i2c(boost::uint8_t addr, const byte_vector_t &bytes){
+    return _iface->write_i2c(addr, bytes);
+}
+
+byte_vector_t b100_dboard_iface::read_i2c(boost::uint8_t addr, size_t num_bytes){
+    return _iface->read_i2c(addr, num_bytes);
+}
+
+/***********************************************************************
+ * Aux DAX/ADC
+ **********************************************************************/
+void b100_dboard_iface::write_aux_dac(dboard_iface::unit_t, aux_dac_t which, double value){
+    //same aux dacs for each unit
+    static const uhd::dict<aux_dac_t, b100_codec_ctrl::aux_dac_t> which_to_aux_dac = map_list_of
+        (AUX_DAC_A, b100_codec_ctrl::AUX_DAC_A)
+        (AUX_DAC_B, b100_codec_ctrl::AUX_DAC_B)
+        (AUX_DAC_C, b100_codec_ctrl::AUX_DAC_C)
+        (AUX_DAC_D, b100_codec_ctrl::AUX_DAC_D)
+    ;
+    _codec->write_aux_dac(which_to_aux_dac[which], value);
+}
+
+double b100_dboard_iface::read_aux_adc(dboard_iface::unit_t unit, aux_adc_t which){
+    static const uhd::dict<
+        unit_t, uhd::dict<aux_adc_t, b100_codec_ctrl::aux_adc_t>
+    > unit_to_which_to_aux_adc = map_list_of
+        (UNIT_RX, map_list_of
+            (AUX_ADC_A, b100_codec_ctrl::AUX_ADC_A1)
+            (AUX_ADC_B, b100_codec_ctrl::AUX_ADC_B1)
+        )
+        (UNIT_TX, map_list_of
+            (AUX_ADC_A, b100_codec_ctrl::AUX_ADC_A2)
+            (AUX_ADC_B, b100_codec_ctrl::AUX_ADC_B2)
+        )
+    ;
+    return _codec->read_aux_adc(unit_to_which_to_aux_adc[unit][which]);
+}
diff --git a/host/lib/usrp/b100/dboard_impl.cpp b/host/lib/usrp/b100/dboard_impl.cpp
new file mode 100644
index 000000000..ba3776728
--- /dev/null
+++ b/host/lib/usrp/b100/dboard_impl.cpp
@@ -0,0 +1,185 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_impl.hpp"
+#include "b100_regs.hpp"
+#include <uhd/exception.hpp>
+#include <uhd/usrp/dboard_props.hpp>
+#include <uhd/usrp/subdev_props.hpp>
+#include <uhd/usrp/misc_utils.hpp>
+#include <boost/bind.hpp>
+#include "usrp_i2c_addr.h"
+
+using namespace uhd;
+using namespace uhd::usrp;
+
+/***********************************************************************
+ * Dboard Initialization
+ **********************************************************************/
+void b100_impl::dboard_init(void){
+    //read the tx and rx dboard eeproms
+    _rx_db_eeprom.load(*_iface, I2C_ADDR_RX_A);
+    _tx_db_eeprom.load(*_iface, I2C_ADDR_TX_A);
+    _gdb_eeprom.load(*_iface, I2C_ADDR_TX_A ^ 5);
+
+    //create a new dboard interface and manager
+    _dboard_iface = make_b100_dboard_iface(
+        _iface, _clock_ctrl, _codec_ctrl
+    );
+    _dboard_manager = dboard_manager::make(
+        _rx_db_eeprom.id,
+        ((_gdb_eeprom.id == dboard_id_t::none())? _tx_db_eeprom : _gdb_eeprom).id,
+        _dboard_iface
+    );
+
+    //setup the dboard proxies
+    _rx_dboard_proxy = wax_obj_proxy::make(
+        boost::bind(&b100_impl::rx_dboard_get, this, _1, _2),
+        boost::bind(&b100_impl::rx_dboard_set, this, _1, _2)
+    );
+    _tx_dboard_proxy = wax_obj_proxy::make(
+        boost::bind(&b100_impl::tx_dboard_get, this, _1, _2),
+        boost::bind(&b100_impl::tx_dboard_set, this, _1, _2)
+    );
+}
+
+/***********************************************************************
+ * RX Dboard Get
+ **********************************************************************/
+void b100_impl::rx_dboard_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<dboard_prop_t>()){
+    case DBOARD_PROP_NAME:
+        val = std::string("b100 dboard (rx unit)");
+        return;
+
+    case DBOARD_PROP_SUBDEV:
+        val = _dboard_manager->get_rx_subdev(key.name);
+        return;
+
+    case DBOARD_PROP_SUBDEV_NAMES:
+        val = _dboard_manager->get_rx_subdev_names();
+        return;
+
+    case DBOARD_PROP_DBOARD_EEPROM:
+        val = _rx_db_eeprom;
+        return;
+
+    case DBOARD_PROP_DBOARD_IFACE:
+        val = _dboard_iface;
+        return;
+
+    case DBOARD_PROP_CODEC:
+        val = _rx_codec_proxy->get_link();
+        return;
+
+    case DBOARD_PROP_GAIN_GROUP:
+        val = make_gain_group(
+            _rx_db_eeprom.id,
+            _dboard_manager->get_rx_subdev(key.name),
+            _rx_codec_proxy->get_link(),
+            GAIN_GROUP_POLICY_RX
+        );
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * RX Dboard Set
+ **********************************************************************/
+void b100_impl::rx_dboard_set(const wax::obj &key, const wax::obj &val){
+    switch(key.as<dboard_prop_t>()){
+    case DBOARD_PROP_DBOARD_EEPROM:
+        _rx_db_eeprom = val.as<dboard_eeprom_t>();
+        _rx_db_eeprom.store(*_iface, I2C_ADDR_RX_A);
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * TX Dboard Get
+ **********************************************************************/
+void b100_impl::tx_dboard_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<dboard_prop_t>()){
+    case DBOARD_PROP_NAME:
+        val = std::string("b100 dboard (tx unit)");
+        return;
+
+    case DBOARD_PROP_SUBDEV:
+        val = _dboard_manager->get_tx_subdev(key.name);
+        return;
+
+    case DBOARD_PROP_SUBDEV_NAMES:
+        val = _dboard_manager->get_tx_subdev_names();
+        return;
+
+    case DBOARD_PROP_DBOARD_EEPROM:
+        val = _tx_db_eeprom;
+        return;
+
+    case DBOARD_PROP_GBOARD_EEPROM:
+        val = _gdb_eeprom;
+        return;
+
+    case DBOARD_PROP_DBOARD_IFACE:
+        val = _dboard_iface;
+        return;
+
+    case DBOARD_PROP_CODEC:
+        val = _tx_codec_proxy->get_link();
+        return;
+
+    case DBOARD_PROP_GAIN_GROUP:
+        val = make_gain_group(
+            _tx_db_eeprom.id,
+            _dboard_manager->get_tx_subdev(key.name),
+            _tx_codec_proxy->get_link(),
+            GAIN_GROUP_POLICY_TX
+        );
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * TX Dboard Set
+ **********************************************************************/
+void b100_impl::tx_dboard_set(const wax::obj &key, const wax::obj &val){
+    switch(key.as<dboard_prop_t>()){
+    case DBOARD_PROP_DBOARD_EEPROM:
+        _tx_db_eeprom = val.as<dboard_eeprom_t>();
+        _tx_db_eeprom.store(*_iface, I2C_ADDR_TX_A);
+        return;
+
+    case DBOARD_PROP_GBOARD_EEPROM:
+        _gdb_eeprom = val.as<dboard_eeprom_t>();
+        _gdb_eeprom.store(*_iface, I2C_ADDR_TX_A ^ 5);
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
diff --git a/host/lib/usrp/b100/dsp_impl.cpp b/host/lib/usrp/b100/dsp_impl.cpp
new file mode 100644
index 000000000..c1bf6bedd
--- /dev/null
+++ b/host/lib/usrp/b100/dsp_impl.cpp
@@ -0,0 +1,189 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_impl.hpp"
+#include "b100_regs.hpp"
+#include <uhd/usrp/dsp_utils.hpp>
+#include <uhd/usrp/dsp_props.hpp>
+#include <boost/math/special_functions/round.hpp>
+#include <boost/bind.hpp>
+
+#define rint boost::math::iround
+
+using namespace uhd;
+using namespace uhd::usrp;
+
+static const double MASTER_CLOCK_RATE = 64e6; //TODO get from clock control
+
+/***********************************************************************
+ * RX DDC Initialization
+ **********************************************************************/
+void b100_impl::rx_ddc_init(void){
+    _rx_ddc_proxy = wax_obj_proxy::make(
+        boost::bind(&b100_impl::rx_ddc_get, this, _1, _2),
+        boost::bind(&b100_impl::rx_ddc_set, this, _1, _2)
+    );
+
+    //initial config and update
+    rx_ddc_set(DSP_PROP_FREQ_SHIFT, double(0));
+    rx_ddc_set(DSP_PROP_HOST_RATE, double(16e6));
+}
+
+/***********************************************************************
+ * RX DDC Get
+ **********************************************************************/
+void b100_impl::rx_ddc_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    switch(key.as<dsp_prop_t>()){
+    case DSP_PROP_NAME:
+        val = std::string("USRP-B100 RX DSP");
+        return;
+
+    case DSP_PROP_OTHERS:
+        val = prop_names_t(); //empty
+        return;
+
+    case DSP_PROP_FREQ_SHIFT:
+        val = _ddc_freq;
+        return;
+
+    case DSP_PROP_CODEC_RATE:
+        val = _clock_ctrl->get_fpga_clock_rate();
+        return;
+
+    case DSP_PROP_HOST_RATE:
+        val = _clock_ctrl->get_fpga_clock_rate()/_ddc_decim;
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * RX DDC Set
+ **********************************************************************/
+void b100_impl::rx_ddc_set(const wax::obj &key_, const wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    switch(key.as<dsp_prop_t>()){
+    case DSP_PROP_STREAM_CMD:
+        issue_stream_cmd(val.as<stream_cmd_t>());
+        return;
+
+    case DSP_PROP_FREQ_SHIFT:{
+            double new_freq = val.as<double>();
+            _iface->poke32(B100_REG_DSP_RX_FREQ,
+                dsp_type1::calc_cordic_word_and_update(new_freq, _clock_ctrl->get_fpga_clock_rate())
+            );
+            _ddc_freq = new_freq; //shadow
+        }
+        return;
+
+    case DSP_PROP_HOST_RATE:{
+            //set the decimation
+            _ddc_decim = rint(_clock_ctrl->get_fpga_clock_rate()/val.as<double>());
+            _iface->poke32(B100_REG_DSP_RX_DECIM_RATE, dsp_type1::calc_cic_filter_word(_ddc_decim));
+
+            //set the scaling
+            static const boost::int16_t default_rx_scale_iq = 1024;
+            _iface->poke32(B100_REG_DSP_RX_SCALE_IQ,
+                dsp_type1::calc_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq)
+            );
+        }
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * TX DUC Initialization
+ **********************************************************************/
+void b100_impl::tx_duc_init(void){
+    _tx_duc_proxy = wax_obj_proxy::make(
+        boost::bind(&b100_impl::tx_duc_get, this, _1, _2),
+        boost::bind(&b100_impl::tx_duc_set, this, _1, _2)
+    );
+
+    //initial config and update
+    tx_duc_set(DSP_PROP_FREQ_SHIFT, double(0));
+    tx_duc_set(DSP_PROP_HOST_RATE, double(16e6));
+}
+
+/***********************************************************************
+ * TX DUC Get
+ **********************************************************************/
+void b100_impl::tx_duc_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    switch(key.as<dsp_prop_t>()){
+    case DSP_PROP_NAME:
+        val = std::string("USRP-B100 TX DSP");
+        return;
+
+    case DSP_PROP_OTHERS:
+        val = prop_names_t(); //empty
+        return;
+
+    case DSP_PROP_FREQ_SHIFT:
+        val = _duc_freq;
+        return;
+
+    case DSP_PROP_CODEC_RATE:
+        val = _clock_ctrl->get_fpga_clock_rate();
+        return;
+
+    case DSP_PROP_HOST_RATE:
+        val = _clock_ctrl->get_fpga_clock_rate()/_duc_interp;
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * TX DUC Set
+ **********************************************************************/
+void b100_impl::tx_duc_set(const wax::obj &key_, const wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    switch(key.as<dsp_prop_t>()){
+
+    case DSP_PROP_FREQ_SHIFT:{
+            double new_freq = val.as<double>();
+            _iface->poke32(B100_REG_DSP_TX_FREQ,
+                dsp_type1::calc_cordic_word_and_update(new_freq, _clock_ctrl->get_fpga_clock_rate())
+            );
+            _duc_freq = new_freq; //shadow
+        }
+        return;
+
+    case DSP_PROP_HOST_RATE:{
+            _duc_interp = rint(_clock_ctrl->get_fpga_clock_rate()/val.as<double>());
+
+            //set the interpolation
+            _iface->poke32(B100_REG_DSP_TX_INTERP_RATE, dsp_type1::calc_cic_filter_word(_duc_interp));
+
+            //set the scaling
+            _iface->poke32(B100_REG_DSP_TX_SCALE_IQ, dsp_type1::calc_iq_scale_word(_duc_interp));
+        }
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
diff --git a/host/lib/usrp/b100/io_impl.cpp b/host/lib/usrp/b100/io_impl.cpp
new file mode 100644
index 000000000..3978bea75
--- /dev/null
+++ b/host/lib/usrp/b100/io_impl.cpp
@@ -0,0 +1,210 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "../../transport/super_recv_packet_handler.hpp"
+#include "../../transport/super_send_packet_handler.hpp"
+#include "usrp_commands.h"
+#include "b100_impl.hpp"
+#include "b100_regs.hpp"
+#include <uhd/usrp/dsp_utils.hpp>
+#include <uhd/usrp/dsp_props.hpp>
+#include <uhd/utils/thread_priority.hpp>
+#include <uhd/transport/bounded_buffer.hpp>
+#include <boost/bind.hpp>
+#include <boost/format.hpp>
+#include <boost/asio.hpp>
+#include <boost/bind.hpp>
+#include <boost/thread.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/utils/log.hpp>
+#include <iostream>
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace uhd::transport;
+namespace asio = boost::asio;
+
+/***********************************************************************
+ * IO Implementation Details
+ **********************************************************************/
+struct b100_impl::io_impl{
+    io_impl(zero_copy_if::sptr data_transport):
+        data_transport(data_transport)
+    {
+        /* NOP */
+    }
+
+    ~io_impl(void){
+        //drain the rx buffs
+        //while(data_transport->get_recv_buff().get() != NULL){
+                /* NOP */
+        //}
+    }
+
+    zero_copy_if::sptr &data_transport;
+
+    sph::recv_packet_handler recv_handler;
+    sph::send_packet_handler send_handler;
+    bool continuous_streaming;
+};
+
+/***********************************************************************
+ * Initialize internals within this file
+ **********************************************************************/
+void b100_impl::io_init(void){
+    _recv_otw_type.width = 16;
+    _recv_otw_type.shift = 0;
+    _recv_otw_type.byteorder = otw_type_t::BO_LITTLE_ENDIAN;
+
+    _send_otw_type.width = 16;
+    _send_otw_type.shift = 0;
+    _send_otw_type.byteorder = otw_type_t::BO_LITTLE_ENDIAN;
+    
+    _iface->reset_gpif(6);
+
+    //reset state machines
+    _iface->poke32(B100_REG_CTRL_TX_CLEAR_UNDERRUN, 0);
+    _iface->poke32(B100_REG_CTRL_RX_CLEAR_OVERRUN, 0);
+
+    _io_impl = UHD_PIMPL_MAKE(io_impl, (_data_transport));
+    
+    //setup rx data path
+    _iface->poke32(B100_REG_CTRL_RX_NSAMPS_PER_PKT, get_max_recv_samps_per_packet());
+    UHD_LOGV(always) << "IO: Using " << get_max_recv_samps_per_packet() << " samples per packet" << std::endl;
+    _iface->poke32(B100_REG_CTRL_RX_NCHANNELS, 1);
+    _iface->poke32(B100_REG_CTRL_RX_VRT_HEADER, 0
+        | (0x1 << 28) //if data with stream id
+        | (0x1 << 26) //has trailer
+        | (0x3 << 22) //integer time other
+        | (0x1 << 20) //fractional time sample count
+    );
+    _iface->poke32(B100_REG_CTRL_RX_VRT_TRAILER, 0);
+
+    //set the streamid to reset the seq num
+    _iface->poke32(B100_REG_CTRL_TX_REPORT_SID, 0);
+    //setup the tx policy
+    _iface->poke32(B100_REG_CTRL_TX_POLICY, B100_FLAG_CTRL_TX_POLICY_NEXT_PACKET);
+    
+    //set the expected packet size in USB frames
+    _iface->poke32(B100_REG_MISC_RX_LEN, 4);
+
+    update_transport_channel_mapping();
+}
+
+void b100_impl::update_transport_channel_mapping(void){
+    if (_io_impl.get() == NULL) return; //not inited yet
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock recv_lock = _io_impl->recv_handler.get_scoped_lock();
+    _io_impl->recv_handler.resize(_rx_subdev_spec.size());
+    _io_impl->recv_handler.set_vrt_unpacker(&vrt::if_hdr_unpack_le);
+    _io_impl->recv_handler.set_tick_rate(_clock_ctrl->get_fpga_clock_rate());
+    _io_impl->recv_handler.set_samp_rate(_rx_ddc_proxy->get_link()[DSP_PROP_HOST_RATE].as<double>());
+    for (size_t chan = 0; chan < _io_impl->recv_handler.size(); chan++){
+        _io_impl->recv_handler.set_xport_chan_get_buff(chan, boost::bind(
+            &uhd::transport::zero_copy_if::get_recv_buff, _io_impl->data_transport, _1
+        ));
+        _io_impl->recv_handler.set_overflow_handler(chan, boost::bind(
+            &b100_impl::handle_overrun, this, chan
+        ));
+    }
+    _io_impl->recv_handler.set_converter(_recv_otw_type);
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock send_lock = _io_impl->send_handler.get_scoped_lock();
+    _io_impl->send_handler.resize(_tx_subdev_spec.size());
+    _io_impl->send_handler.set_vrt_packer(&vrt::if_hdr_pack_le);
+    _io_impl->send_handler.set_tick_rate(_clock_ctrl->get_fpga_clock_rate());
+    _io_impl->send_handler.set_samp_rate(_tx_duc_proxy->get_link()[DSP_PROP_HOST_RATE].as<double>());
+    for (size_t chan = 0; chan < _io_impl->send_handler.size(); chan++){
+        _io_impl->send_handler.set_xport_chan_get_buff(chan, boost::bind(
+            &uhd::transport::zero_copy_if::get_send_buff, _io_impl->data_transport, _1
+        ));
+    }
+    _io_impl->send_handler.set_converter(_send_otw_type);
+    _io_impl->send_handler.set_max_samples_per_packet(get_max_send_samps_per_packet());
+}
+
+/***********************************************************************
+ * Data send + helper functions
+ **********************************************************************/
+size_t b100_impl::get_max_send_samps_per_packet(void) const {
+    static const size_t hdr_size = 0
+        + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
+        - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
+    ;
+    static const size_t bpp = 2048 - hdr_size;
+    return bpp / _send_otw_type.get_sample_size();
+}
+
+size_t b100_impl::send(
+    const send_buffs_type &buffs, size_t nsamps_per_buff,
+    const tx_metadata_t &metadata, const io_type_t &io_type,
+    send_mode_t send_mode, double timeout
+){    
+    return _io_impl->send_handler.send(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        send_mode, timeout
+    );
+}
+
+/***********************************************************************
+ * Data recv + helper functions
+ **********************************************************************/
+
+size_t b100_impl::get_max_recv_samps_per_packet(void) const {
+    static const size_t hdr_size = 0
+        + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
+        + sizeof(vrt::if_packet_info_t().tlr) //forced to have trailer
+        - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
+    ;
+    size_t bpp = 2048 - hdr_size; //limited by FPGA pkt buffer size
+    return bpp/_recv_otw_type.get_sample_size();
+}
+
+size_t b100_impl::recv(
+    const recv_buffs_type &buffs, size_t nsamps_per_buff,
+    rx_metadata_t &metadata, const io_type_t &io_type,
+    recv_mode_t recv_mode, double timeout
+){
+    return _io_impl->recv_handler.recv(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        recv_mode, timeout
+    );
+}
+
+void b100_impl::issue_stream_cmd(const stream_cmd_t &stream_cmd)
+{
+    _io_impl->continuous_streaming = (stream_cmd.stream_mode == stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
+    _iface->poke32(B100_REG_CTRL_RX_STREAM_CMD, dsp_type1::calc_stream_cmd_word(stream_cmd));
+    _iface->poke32(B100_REG_CTRL_RX_TIME_SECS,  boost::uint32_t(stream_cmd.time_spec.get_full_secs()));
+    _iface->poke32(B100_REG_CTRL_RX_TIME_TICKS, stream_cmd.time_spec.get_tick_count(_clock_ctrl->get_fpga_clock_rate()));
+    
+    if (stream_cmd.stream_mode == stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS) {
+        while(_io_impl->data_transport->get_recv_buff().get() != NULL){
+            /* NOP */
+        }
+    }
+}
+
+void b100_impl::handle_overrun(size_t){
+    if (_io_impl->continuous_streaming){
+        this->issue_stream_cmd(stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
+    }
+}
diff --git a/host/lib/usrp/b100/mboard_impl.cpp b/host/lib/usrp/b100/mboard_impl.cpp
new file mode 100644
index 000000000..c651ff2a2
--- /dev/null
+++ b/host/lib/usrp/b100/mboard_impl.cpp
@@ -0,0 +1,246 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include "b100_impl.hpp"
+#include "usrp_commands.h"
+#include "fpga_regs_standard.h"
+#include "fpga_regs_common.h"
+#include "b100_regs.hpp"
+#include "usrp_i2c_addr.h"
+#include <uhd/usrp/misc_utils.hpp>
+#include <uhd/usrp/mboard_props.hpp>
+#include <uhd/usrp/dboard_props.hpp>
+#include <uhd/usrp/subdev_props.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/exception.hpp>
+#include <uhd/utils/images.hpp>
+#include <boost/assign/list_of.hpp>
+#include <boost/foreach.hpp>
+#include <boost/bind.hpp>
+#include <boost/thread/thread.hpp>
+#include <uhd/usrp/dsp_utils.hpp>
+
+using namespace uhd;
+using namespace uhd::usrp;
+
+static const bool b100_mboard_verbose = true;
+
+/***********************************************************************
+ * Mboard Initialization
+ **********************************************************************/
+void b100_impl::mboard_init(void)
+{
+    _mboard_proxy = wax_obj_proxy::make(
+                     boost::bind(&b100_impl::mboard_get, this, _1, _2),
+                     boost::bind(&b100_impl::mboard_set, this, _1, _2));
+
+    //set the ticks per seconds into the vita time control
+    _iface->poke32(B100_REG_TIME64_TPS,
+        boost::uint32_t(_clock_ctrl->get_fpga_clock_rate())
+    );
+    
+    //init the clock config
+    _clock_config = clock_config_t::internal();
+    update_clock_config();
+}
+
+void b100_impl::update_clock_config(void){
+    boost::uint32_t pps_flags = 0;
+
+    //translate pps polarity enums
+    switch(_clock_config.pps_polarity){
+    case clock_config_t::PPS_POS: pps_flags |= B100_FLAG_TIME64_PPS_POSEDGE; break;
+    case clock_config_t::PPS_NEG: pps_flags |= B100_FLAG_TIME64_PPS_NEGEDGE; break;
+    default: throw uhd::runtime_error("unhandled clock configuration pps polarity");
+    }
+
+    //set the pps flags
+    _iface->poke32(B100_REG_TIME64_FLAGS, pps_flags);
+
+    //clock source ref 10mhz
+    switch(_clock_config.ref_source){
+    case clock_config_t::REF_AUTO: _clock_ctrl->use_auto_ref(); break;
+    case clock_config_t::REF_INT: _clock_ctrl->use_internal_ref(); break;
+    case clock_config_t::REF_SMA: _clock_ctrl->use_auto_ref(); break;
+    default: throw uhd::runtime_error("unhandled clock configuration ref source");
+    }
+}
+
+/***********************************************************************
+ * Mboard Get
+ **********************************************************************/
+void b100_impl::mboard_get(const wax::obj &key_, wax::obj &val){
+    named_prop_t key = named_prop_t::extract(key_);
+
+    //handle the get request conditioned on the key
+    switch(key.as<mboard_prop_t>()){
+    case MBOARD_PROP_NAME:
+        val = std::string("USRP-B100 mboard");
+        return;
+
+    case MBOARD_PROP_OTHERS:
+        val = prop_names_t();
+        return;
+
+    case MBOARD_PROP_RX_DBOARD:
+        UHD_ASSERT_THROW(key.name == "");
+        val = _rx_dboard_proxy->get_link();
+        return;
+
+    case MBOARD_PROP_RX_DBOARD_NAMES:
+        val = prop_names_t(1, ""); //vector of size 1 with empty string
+        return;
+
+    case MBOARD_PROP_TX_DBOARD:
+        UHD_ASSERT_THROW(key.name == "");
+        val = _tx_dboard_proxy->get_link();
+        return;
+
+    case MBOARD_PROP_TX_DBOARD_NAMES:
+        val = prop_names_t(1, ""); //vector of size 1 with empty string
+        return;
+
+    case MBOARD_PROP_RX_DSP:
+        UHD_ASSERT_THROW(key.name == "");
+        val = _rx_ddc_proxy->get_link();
+        return;
+
+    case MBOARD_PROP_RX_DSP_NAMES:
+        val = prop_names_t(1, "");
+        return;
+
+    case MBOARD_PROP_TX_DSP:
+        UHD_ASSERT_THROW(key.name == "");
+        val = _tx_duc_proxy->get_link();
+        return;
+
+    case MBOARD_PROP_TX_DSP_NAMES:
+        val = prop_names_t(1, "");
+        return;
+
+    case MBOARD_PROP_CLOCK_CONFIG:
+        val = _clock_config;
+        return;
+
+    case MBOARD_PROP_RX_SUBDEV_SPEC:
+        val = _rx_subdev_spec;
+        return;
+
+    case MBOARD_PROP_TX_SUBDEV_SPEC:
+        val = _tx_subdev_spec;
+        return;
+        
+    case MBOARD_PROP_EEPROM_MAP:
+        val = _iface->mb_eeprom;
+        return;
+
+    case MBOARD_PROP_TIME_NOW:while(true){
+        uint32_t secs = _iface->peek32(B100_REG_RB_TIME_NOW_SECS);
+        uint32_t ticks = _iface->peek32(B100_REG_RB_TIME_NOW_TICKS);
+        if (secs != _iface->peek32(B100_REG_RB_TIME_NOW_SECS)) continue;
+        val = time_spec_t(secs, ticks, _clock_ctrl->get_fpga_clock_rate());
+        return;
+    }
+    
+    case MBOARD_PROP_TIME_PPS: while(true){
+        uint32_t secs = _iface->peek32(B100_REG_RB_TIME_PPS_SECS);
+        uint32_t ticks = _iface->peek32(B100_REG_RB_TIME_PPS_TICKS);
+        if (secs != _iface->peek32(B100_REG_RB_TIME_PPS_SECS)) continue;
+        val = time_spec_t(secs, ticks, _clock_ctrl->get_fpga_clock_rate());
+        return;
+    }
+
+    case MBOARD_PROP_CLOCK_RATE:
+        val = _clock_ctrl->get_fpga_clock_rate();
+        return;
+
+    default: UHD_THROW_PROP_GET_ERROR();
+    }
+}
+
+/***********************************************************************
+ * Mboard Set
+ **********************************************************************/
+void b100_impl::mboard_set(const wax::obj &key, const wax::obj &val)
+{
+    if(key.type() == typeid(std::string)) {
+      if(key.as<std::string>() == "load_eeprom") {
+        std::string b100_eeprom_image = val.as<std::string>();
+        UHD_MSG(status) << "B100 EEPROM image: " << b100_eeprom_image << std::endl;
+        _fx2_ctrl->usrp_load_eeprom(val.as<std::string>());
+      }
+      return;
+   	}
+
+    //handle the get request conditioned on the key
+    switch(key.as<mboard_prop_t>()){
+    case MBOARD_PROP_TIME_NOW:
+    case MBOARD_PROP_TIME_PPS:{
+            time_spec_t time_spec = val.as<time_spec_t>();
+            _iface->poke32(B100_REG_TIME64_TICKS, time_spec.get_tick_count(_clock_ctrl->get_fpga_clock_rate()));
+            boost::uint32_t imm_flags = (key.as<mboard_prop_t>() == MBOARD_PROP_TIME_NOW)? 1 : 0;
+            _iface->poke32(B100_REG_TIME64_IMM, imm_flags);
+            _iface->poke32(B100_REG_TIME64_SECS, boost::uint32_t(time_spec.get_full_secs()));
+        }
+        return;
+
+    case MBOARD_PROP_RX_SUBDEV_SPEC:
+        _rx_subdev_spec = val.as<subdev_spec_t>();
+        verify_rx_subdev_spec(_rx_subdev_spec, _mboard_proxy->get_link());
+        UHD_ASSERT_THROW(_rx_subdev_spec.size() == 1);
+        //set the mux
+        _iface->poke32(B100_REG_DSP_RX_MUX, dsp_type1::calc_rx_mux_word(
+            _dboard_manager->get_rx_subdev(_rx_subdev_spec.front().sd_name)[SUBDEV_PROP_CONNECTION].as<subdev_conn_t>()
+        ));
+        return;
+
+    case MBOARD_PROP_TX_SUBDEV_SPEC:
+        _tx_subdev_spec = val.as<subdev_spec_t>();
+        verify_tx_subdev_spec(_tx_subdev_spec, _mboard_proxy->get_link());
+        UHD_ASSERT_THROW(_tx_subdev_spec.size() == 1);
+        //set the mux and set the number of tx channels
+        _iface->poke32(B100_REG_DSP_TX_MUX, dsp_type1::calc_tx_mux_word(
+            _dboard_manager->get_tx_subdev(_tx_subdev_spec.front().sd_name)[SUBDEV_PROP_CONNECTION].as<subdev_conn_t>()
+        ));
+        return;
+
+    case MBOARD_PROP_EEPROM_MAP:
+        // Step1: commit the map, writing only those values set.
+        // Step2: readback the entire eeprom map into the iface.
+        val.as<mboard_eeprom_t>().commit(*_iface, mboard_eeprom_t::MAP_B000);
+        _iface->mb_eeprom = mboard_eeprom_t(*_iface, mboard_eeprom_t::MAP_B000);
+        return;
+
+    case MBOARD_PROP_CLOCK_CONFIG:
+        _clock_config = val.as<clock_config_t>();
+        update_clock_config();
+        return;
+
+    case MBOARD_PROP_CLOCK_RATE:
+        UHD_MSG(warning)
+            << "You are setting the master clock rate from the API.\n"
+            << "You may want to pass this into the device address as master_clock_rate=<rate>.\n"
+            << "This way, the clock rate is guaranteed to be initialized first.\n"
+            << "See the application notes for USRP-B100 for further instructions.\n"
+        ;
+        _clock_ctrl->set_fpga_clock_rate(val.as<double>());
+        update_transport_channel_mapping();
+        return;
+
+    default: UHD_THROW_PROP_SET_ERROR();
+    }
+}
diff --git a/host/lib/usrp/dboard/db_basic_and_lf.cpp b/host/lib/usrp/dboard/db_basic_and_lf.cpp
index 6f8de9a7b..566e24d97 100644
--- a/host/lib/usrp/dboard/db_basic_and_lf.cpp
+++ b/host/lib/usrp/dboard/db_basic_and_lf.cpp
@@ -111,6 +111,7 @@ basic_rx::basic_rx(ctor_args_t args, double max_freq) : rx_dboard_base(args){
     this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, 0x0000);
     this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, 0xFFFF);
     this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0x0000);
+    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_RX, true);
 }
 
 basic_rx::~basic_rx(void){
@@ -216,6 +217,7 @@ void basic_rx::rx_set(const wax::obj &key_, const wax::obj &val){
  **********************************************************************/
 basic_tx::basic_tx(ctor_args_t args, double max_freq) : tx_dboard_base(args){
     _max_freq = max_freq;
+    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_TX, true);
 }
 
 basic_tx::~basic_tx(void){
diff --git a/host/lib/usrp/fx2/fx2_ctrl.hpp b/host/lib/usrp/fx2/fx2_ctrl.hpp
index 98c98bb8c..37fa09605 100644
--- a/host/lib/usrp/fx2/fx2_ctrl.hpp
+++ b/host/lib/usrp/fx2/fx2_ctrl.hpp
@@ -57,7 +57,7 @@ public:
      * \param filename name of EEPROM image
      */
     virtual void usrp_load_eeprom(std::string filestring) = 0;
-
+    
     /*!
      * Submit an IN transfer 
      * \param request device specific request 
diff --git a/host/lib/usrp/usrp1/dsp_impl.cpp b/host/lib/usrp/usrp1/dsp_impl.cpp
index 66b11b989..0bddc49f0 100644
--- a/host/lib/usrp/usrp1/dsp_impl.cpp
+++ b/host/lib/usrp/usrp1/dsp_impl.cpp
@@ -114,6 +114,7 @@ void usrp1_impl::rx_dsp_set(const wax::obj &key_, const wax::obj &val, size_t wh
             _iface->poke32(FR_DECIM_RATE, _rx_dsp_decim/2 - 1);
             this->restore_rx(s);
         }
+        this->update_xport_channel_mapping(); //rate changed -> update
         return;
 
     case DSP_PROP_STREAM_CMD:
@@ -211,8 +212,10 @@ void usrp1_impl::tx_dsp_set(const wax::obj &key_, const wax::obj &val, size_t wh
             bool s = this->disable_tx();
             _iface->poke32(FR_INTERP_RATE, _tx_dsp_interp/2 - 1);
             this->restore_tx(s);
-            return;
         }
+        this->update_xport_channel_mapping(); //rate changed -> update
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 
diff --git a/host/lib/usrp/usrp1/io_impl.cpp b/host/lib/usrp/usrp1/io_impl.cpp
index 8ac2696eb..90ed17cd8 100644
--- a/host/lib/usrp/usrp1/io_impl.cpp
+++ b/host/lib/usrp/usrp1/io_impl.cpp
@@ -15,12 +15,15 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include "../../transport/vrt_packet_handler.hpp"
+#define SRPH_DONT_CHECK_SEQUENCE
+#include "../../transport/super_recv_packet_handler.hpp"
+#include "../../transport/super_send_packet_handler.hpp"
 #include "usrp_commands.h"
 #include "usrp1_impl.hpp"
 #include <uhd/utils/msg.hpp>
 #include <uhd/utils/safe_call.hpp>
 #include <uhd/utils/thread_priority.hpp>
+#include <uhd/usrp/dsp_props.hpp>
 #include <uhd/transport/bounded_buffer.hpp>
 #include <boost/bind.hpp>
 #include <boost/format.hpp>
@@ -88,13 +91,39 @@ private:
 };
 
 /***********************************************************************
+ * BS VRT packer/unpacker functions (since samples don't have headers)
+ **********************************************************************/
+static void usrp1_bs_vrt_packer(
+    boost::uint32_t *,
+    vrt::if_packet_info_t &if_packet_info
+){
+    if_packet_info.num_header_words32 = 0;
+    if_packet_info.num_packet_words32 = if_packet_info.num_payload_words32;
+}
+
+static void usrp1_bs_vrt_unpacker(
+    const boost::uint32_t *,
+    vrt::if_packet_info_t &if_packet_info
+){
+    if_packet_info.packet_type = vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    if_packet_info.num_payload_words32 = if_packet_info.num_packet_words32;
+    if_packet_info.num_header_words32 = 0;
+    if_packet_info.packet_count = 0;
+    if_packet_info.sob = false;
+    if_packet_info.eob = false;
+    if_packet_info.has_sid = false;
+    if_packet_info.has_cid = false;
+    if_packet_info.has_tsi = false;
+    if_packet_info.has_tsf = false;
+    if_packet_info.has_tlr = false;
+}
+
+/***********************************************************************
  * IO Implementation Details
  **********************************************************************/
 struct usrp1_impl::io_impl{
     io_impl(zero_copy_if::sptr data_transport):
         data_transport(data_transport),
-        get_recv_buffs_fcn(boost::bind(&usrp1_impl::io_impl::get_recv_buffs, this, _1)),
-        get_send_buffs_fcn(boost::bind(&usrp1_impl::io_impl::get_send_buffs, this, _1)),
         underflow_poll_samp_count(0),
         overflow_poll_samp_count(0),
         curr_buff(offset_send_buffer(data_transport->get_send_buff())),
@@ -109,16 +138,9 @@ struct usrp1_impl::io_impl{
 
     zero_copy_if::sptr data_transport;
 
-    //timeouts set on calls to recv/send (passed into get buffs methods)
-    double recv_timeout, send_timeout;
-
-    //bound callbacks for get buffs (bound once here, not in fast-path)
-    vrt_packet_handler::get_recv_buffs_t get_recv_buffs_fcn;
-    vrt_packet_handler::get_send_buffs_t get_send_buffs_fcn;
-
     //state management for the vrt packet handler code
-    vrt_packet_handler::recv_state packet_handler_recv_state;
-    vrt_packet_handler::send_state packet_handler_send_state;
+    sph::recv_packet_handler recv_handler;
+    sph::send_packet_handler send_handler;
 
     //state management for overflow and underflow
     size_t underflow_poll_samp_count;
@@ -132,11 +154,13 @@ struct usrp1_impl::io_impl{
     offset_managed_send_buffer omsb;
     void commit_send_buff(offset_send_buffer&, offset_send_buffer&, size_t);
     void flush_send_buff(void);
-    bool get_send_buffs(vrt_packet_handler::managed_send_buffs_t &);
-    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs){
-        UHD_ASSERT_THROW(buffs.size() == 1);
-        buffs[0] = data_transport->get_recv_buff(recv_timeout);
-        return buffs[0].get() != NULL;
+    managed_send_buffer::sptr get_send_buff(double timeout){
+        //try to get a new managed buffer with timeout
+        offset_send_buffer next_buff(data_transport->get_send_buff(timeout));
+        if (not next_buff.buff.get()) return managed_send_buffer::sptr(); /* propagate timeout here */
+
+        //make a new managed buffer with the offset buffs
+        return omsb.get_new(curr_buff, next_buff);
     }
 };
 
@@ -185,32 +209,13 @@ void usrp1_impl::io_impl::flush_send_buff(void){
     if (bytes_to_pad == 0) bytes_to_pad = alignment_padding;
 
     //get the buffer, clear, and commit (really current buffer)
-    vrt_packet_handler::managed_send_buffs_t buffs(1);
-    if (this->get_send_buffs(buffs)){
-        std::memset(buffs[0]->cast<void *>(), 0, bytes_to_pad);
-        buffs[0]->commit(bytes_to_pad);
+    managed_send_buffer::sptr buff = this->get_send_buff(.1);
+    if (buff.get() != NULL){
+        std::memset(buff->cast<void *>(), 0, bytes_to_pad);
+        buff->commit(bytes_to_pad);
     }
 }
 
-/*!
- * Get a managed send buffer with the alignment padding:
- * Always grab the next send buffer so we can timeout here.
- */
-bool usrp1_impl::io_impl::get_send_buffs(
-    vrt_packet_handler::managed_send_buffs_t &buffs
-){
-    UHD_ASSERT_THROW(buffs.size() == 1);
-
-    //try to get a new managed buffer with timeout
-    offset_send_buffer next_buff(data_transport->get_send_buff(send_timeout));
-    if (not next_buff.buff.get()) return false; /* propagate timeout here */
-
-    //make a new managed buffer with the offset buffs
-    buffs[0] = omsb.get_new(curr_buff, next_buff);
-
-    return true;
-}
-
 /***********************************************************************
  * Initialize internals within this file
  **********************************************************************/
@@ -232,6 +237,34 @@ void usrp1_impl::io_init(void){
     this->enable_tx(true); //always enabled
     rx_stream_on_off(false);
     _io_impl->flush_send_buff();
+
+    //update mapping here since it didnt b4 when io init not called first
+    update_xport_channel_mapping();
+}
+
+void usrp1_impl::update_xport_channel_mapping(void){
+    if (_io_impl.get() == NULL) return; //not inited yet
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock recv_lock = _io_impl->recv_handler.get_scoped_lock();
+    _io_impl->recv_handler.set_vrt_unpacker(&usrp1_bs_vrt_unpacker);
+    _io_impl->recv_handler.set_tick_rate(_clock_ctrl->get_master_clock_freq());
+    _io_impl->recv_handler.set_samp_rate(_rx_dsp_proxies[_rx_dsp_proxies.keys().at(0)]->get_link()[DSP_PROP_HOST_RATE].as<double>());
+    _io_impl->recv_handler.set_xport_chan_get_buff(0, boost::bind(
+        &uhd::transport::zero_copy_if::get_recv_buff, _io_impl->data_transport, _1
+    ));
+    _io_impl->recv_handler.set_converter(_rx_otw_type, _rx_subdev_spec.size());
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock send_lock = _io_impl->send_handler.get_scoped_lock();
+    _io_impl->send_handler.set_vrt_packer(&usrp1_bs_vrt_packer);
+    _io_impl->send_handler.set_tick_rate(_clock_ctrl->get_master_clock_freq());
+    _io_impl->send_handler.set_samp_rate(_tx_dsp_proxies[_tx_dsp_proxies.keys().at(0)]->get_link()[DSP_PROP_HOST_RATE].as<double>());
+    _io_impl->send_handler.set_xport_chan_get_buff(0, boost::bind(
+        &usrp1_impl::io_impl::get_send_buff, _io_impl.get(), _1
+    ));
+    _io_impl->send_handler.set_converter(_tx_otw_type, _tx_subdev_spec.size());
+    _io_impl->send_handler.set_max_samples_per_packet(get_max_send_samps_per_packet());
 }
 
 void usrp1_impl::rx_stream_on_off(bool enb){
@@ -245,14 +278,6 @@ void usrp1_impl::rx_stream_on_off(bool enb){
 /***********************************************************************
  * Data send + helper functions
  **********************************************************************/
-static void usrp1_bs_vrt_packer(
-    boost::uint32_t *,
-    vrt::if_packet_info_t &if_packet_info
-){
-    if_packet_info.num_header_words32 = 0;
-    if_packet_info.num_packet_words32 = if_packet_info.num_payload_words32;
-}
-
 size_t usrp1_impl::get_max_send_samps_per_packet(void) const {
     return (_data_transport->get_send_frame_size() - alignment_padding)
         / _tx_otw_type.get_sample_size()
@@ -261,29 +286,21 @@ size_t usrp1_impl::get_max_send_samps_per_packet(void) const {
 }
 
 size_t usrp1_impl::send(
-    const send_buffs_type &buffs, size_t num_samps,
+    const send_buffs_type &buffs, size_t nsamps_per_buff,
     const tx_metadata_t &metadata, const io_type_t &io_type,
     send_mode_t send_mode, double timeout
 ){
-    if (_soft_time_ctrl->send_pre(metadata, timeout)) return num_samps;
-
-    _io_impl->send_timeout = timeout;
-    size_t num_samps_sent = vrt_packet_handler::send(
-        _io_impl->packet_handler_send_state,       //last state of the send handler
-        buffs, num_samps,                          //buffer to fill
-        metadata, send_mode,                       //samples metadata
-        io_type, _tx_otw_type,                     //input and output types to convert
-        _clock_ctrl->get_master_clock_freq(),      //master clock tick rate
-        &usrp1_bs_vrt_packer,
-        _io_impl->get_send_buffs_fcn,
-        get_max_send_samps_per_packet(),
-        0,                                         //vrt header offset
-        _tx_subdev_spec.size()                     //num channels
+    if (_soft_time_ctrl->send_pre(metadata, timeout)) return 0;
+
+    size_t num_samps_sent = _io_impl->send_handler.send(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        send_mode, timeout
     );
 
     //handle eob flag (commit the buffer, disable the DACs)
     //check num samps sent to avoid flush on incomplete/timeout
-    if (metadata.end_of_burst and num_samps_sent == num_samps){
+    if (metadata.end_of_burst and num_samps_sent == nsamps_per_buff){
         _io_impl->flush_send_buff();
     }
 
@@ -306,23 +323,6 @@ size_t usrp1_impl::send(
 /***********************************************************************
  * Data recv + helper functions
  **********************************************************************/
-static void usrp1_bs_vrt_unpacker(
-    const boost::uint32_t *,
-    vrt::if_packet_info_t &if_packet_info
-){
-    if_packet_info.packet_type = vrt::if_packet_info_t::PACKET_TYPE_DATA;
-    if_packet_info.num_payload_words32 = if_packet_info.num_packet_words32;
-    if_packet_info.num_header_words32 = 0;
-    if_packet_info.packet_count = 0;
-    if_packet_info.sob = false;
-    if_packet_info.eob = false;
-    if_packet_info.has_sid = false;
-    if_packet_info.has_cid = false;
-    if_packet_info.has_tsi = false;
-    if_packet_info.has_tsf = false;
-    if_packet_info.has_tlr = false;
-}
-
 size_t usrp1_impl::get_max_recv_samps_per_packet(void) const {
     return _data_transport->get_recv_frame_size()
         / _rx_otw_type.get_sample_size()
@@ -331,22 +331,14 @@ size_t usrp1_impl::get_max_recv_samps_per_packet(void) const {
 }
 
 size_t usrp1_impl::recv(
-    const recv_buffs_type &buffs, size_t num_samps,
+    const recv_buffs_type &buffs, size_t nsamps_per_buff,
     rx_metadata_t &metadata, const io_type_t &io_type,
     recv_mode_t recv_mode, double timeout
 ){
-    _io_impl->recv_timeout = timeout;
-    size_t num_samps_recvd = vrt_packet_handler::recv(
-        _io_impl->packet_handler_recv_state,       //last state of the recv handler
-        buffs, num_samps,                          //buffer to fill
-        metadata, recv_mode,                       //samples metadata
-        io_type, _rx_otw_type,                     //input and output types to convert
-        _clock_ctrl->get_master_clock_freq(),      //master clock tick rate
-        &usrp1_bs_vrt_unpacker,
-        _io_impl->get_recv_buffs_fcn,
-        &vrt_packet_handler::handle_overflow_nop,
-        0,                                         //vrt header offset
-        _rx_subdev_spec.size()                     //num channels
+    size_t num_samps_recvd = _io_impl->recv_handler.recv(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        recv_mode, timeout
     );
 
     _soft_time_ctrl->recv_post(metadata, num_samps_recvd);
diff --git a/host/lib/usrp/usrp1/mboard_impl.cpp b/host/lib/usrp/usrp1/mboard_impl.cpp
index f699c8e12..a265a5089 100644
--- a/host/lib/usrp/usrp1/mboard_impl.cpp
+++ b/host/lib/usrp/usrp1/mboard_impl.cpp
@@ -352,6 +352,7 @@ void usrp1_impl::mboard_set(const wax::obj &key, const wax::obj &val)
         bool s = this->disable_rx();
         _iface->poke32(FR_RX_MUX, calc_rx_mux(_rx_subdev_spec, _mboard_proxy->get_link()));
         this->restore_rx(s);
+        this->update_xport_channel_mapping();
     }return;
 
     case MBOARD_PROP_TX_SUBDEV_SPEC:{
@@ -367,6 +368,7 @@ void usrp1_impl::mboard_set(const wax::obj &key, const wax::obj &val)
         bool s = this->disable_tx();
         _iface->poke32(FR_TX_MUX, calc_tx_mux(_tx_subdev_spec, _mboard_proxy->get_link()));
         this->restore_tx(s);
+        this->update_xport_channel_mapping();
     }return;
 
     case MBOARD_PROP_EEPROM_MAP:
@@ -387,6 +389,7 @@ void usrp1_impl::mboard_set(const wax::obj &key, const wax::obj &val)
             << "See the application notes for USRP1 for further instructions.\n"
         ;
         _clock_ctrl->set_master_clock_freq(val.as<double>());
+        this->update_xport_channel_mapping();
         return;
 
     case MBOARD_PROP_CLOCK_CONFIG:{
diff --git a/host/lib/usrp/usrp1/usrp1_impl.cpp b/host/lib/usrp/usrp1/usrp1_impl.cpp
index 37955d628..a3d502038 100644
--- a/host/lib/usrp/usrp1/usrp1_impl.cpp
+++ b/host/lib/usrp/usrp1/usrp1_impl.cpp
@@ -199,12 +199,12 @@ usrp1_impl::usrp1_impl(uhd::transport::usb_zero_copy::sptr data_transport,
     //initialize the dsps
     tx_dsp_init();
 
-    //initialize the send/recv
-    io_init();
-
     //init the subdev specs
     this->mboard_set(MBOARD_PROP_RX_SUBDEV_SPEC, subdev_spec_t());
     this->mboard_set(MBOARD_PROP_TX_SUBDEV_SPEC, subdev_spec_t());
+
+    //initialize the send/recv
+    io_init();
 }
 
 usrp1_impl::~usrp1_impl(void){UHD_SAFE_CALL(
diff --git a/host/lib/usrp/usrp1/usrp1_impl.hpp b/host/lib/usrp/usrp1/usrp1_impl.hpp
index fbae2a3b9..bea1dbe3b 100644
--- a/host/lib/usrp/usrp1/usrp1_impl.hpp
+++ b/host/lib/usrp/usrp1/usrp1_impl.hpp
@@ -114,6 +114,9 @@ private:
         const uhd::usrp::dboard_id_t &rx_dboard_id
     );
 
+    //!call when the channel mapping is changed
+    void update_xport_channel_mapping(void);
+
     //soft time control emulation
     uhd::usrp::soft_time_ctrl::sptr _soft_time_ctrl;
 
diff --git a/host/lib/usrp/usrp2/dsp_impl.cpp b/host/lib/usrp/usrp2/dsp_impl.cpp
index 292659f36..03cdeae42 100644
--- a/host/lib/usrp/usrp2/dsp_impl.cpp
+++ b/host/lib/usrp/usrp2/dsp_impl.cpp
@@ -118,12 +118,6 @@ void usrp2_mboard_impl::issue_ddc_stream_cmd(const stream_cmd_t &stream_cmd, siz
     _iface->poke32(U2_REG_RX_CTRL_TIME_TICKS(which_dsp), stream_cmd.time_spec.get_tick_count(get_master_clock_freq()));
 }
 
-void usrp2_mboard_impl::handle_overflow(size_t which_dsp){
-    if (_dsp_impl->continuous_streaming[which_dsp]){ //re-issue the stream command if already continuous
-        this->issue_ddc_stream_cmd(stream_cmd_t::STREAM_MODE_START_CONTINUOUS, which_dsp);
-    }
-}
-
 /***********************************************************************
  * DDC Properties
  **********************************************************************/
@@ -186,6 +180,7 @@ void usrp2_mboard_impl::ddc_set(const wax::obj &key_, const wax::obj &val, size_
                 dsp_type1::calc_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq)
             );
         }
+        _device.update_xport_channel_mapping(); //rate changed -> update
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
@@ -259,6 +254,7 @@ void usrp2_mboard_impl::duc_set(const wax::obj &key_, const wax::obj &val, size_
             //set the scaling
             _iface->poke32(U2_REG_DSP_TX_SCALE_IQ, dsp_type1::calc_iq_scale_word(_dsp_impl->duc_interp[which_dsp]));
         }
+        _device.update_xport_channel_mapping(); //rate changed -> update
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
diff --git a/host/lib/usrp/usrp2/io_impl.cpp b/host/lib/usrp/usrp2/io_impl.cpp
index 33f249599..ffe9a88e7 100644
--- a/host/lib/usrp/usrp2/io_impl.cpp
+++ b/host/lib/usrp/usrp2/io_impl.cpp
@@ -15,18 +15,21 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-#include "../../transport/vrt_packet_handler.hpp"
+#include "../../transport/super_recv_packet_handler.hpp"
+#include "../../transport/super_send_packet_handler.hpp"
 #include "usrp2_impl.hpp"
 #include "usrp2_regs.hpp"
 #include <uhd/utils/log.hpp>
 #include <uhd/utils/msg.hpp>
 #include <uhd/exception.hpp>
 #include <uhd/usrp/mboard_props.hpp>
+#include <uhd/usrp/dsp_props.hpp>
 #include <uhd/utils/byteswap.hpp>
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/transport/bounded_buffer.hpp>
 #include <boost/format.hpp>
 #include <boost/bind.hpp>
+#include <boost/thread/mutex.hpp>
 #include <boost/thread/thread.hpp>
 #include <boost/thread/barrier.hpp>
 #include <iostream>
@@ -80,14 +83,21 @@ public:
     }
 
     /*!
+     * Gets the current sequence number to go out.
+     * Increments the sequence for the next call
+     * \return the sequence to be sent to the dsp
+     */
+    UHD_INLINE seq_type get_curr_seq_out(void){
+        return _last_seq_out++;
+    }
+
+    /*!
      * Check the flow control condition.
-     * \param seq the sequence to go out
      * \param timeout the timeout in seconds
      * \return false on timeout
      */
-    UHD_INLINE bool check_fc_condition(seq_type seq, double timeout){
-        boost::unique_lock<boost::mutex> lock(_fc_mutex);
-        _last_seq_out = seq;
+    UHD_INLINE bool check_fc_condition(double timeout){
+        boost::mutex::scoped_lock lock(_fc_mutex);
         if (this->ready()) return true;
         boost::this_thread::disable_interruption di; //disable because the wait can throw
         return _fc_cond.timed_wait(lock, to_time_dur(timeout), _ready_fcn);
@@ -98,7 +108,7 @@ public:
      * \param seq the last sequence number to be ACK'd
      */
     UHD_INLINE void update_fc_condition(seq_type seq){
-        boost::unique_lock<boost::mutex> lock(_fc_mutex);
+        boost::mutex::scoped_lock lock(_fc_mutex);
         _last_seq_ack = seq;
         lock.unlock();
         _fc_cond.notify_one();
@@ -116,23 +126,6 @@ private:
 };
 
 /***********************************************************************
- * Alignment indexes class: keeps track of indexes
- **********************************************************************/
-class alignment_indexes{
-public:
-    alignment_indexes(void){_indexes = 0;}
-    void reset(size_t len){_indexes = (1 << len) - 1;}
-    size_t front(void){ //TODO replace with look-up table
-        size_t index = 0;
-        while ((_indexes & (1 << index)) == 0) index++;
-        return index;
-    }
-    void remove(size_t index){_indexes &= ~(1 << index);}
-    bool empty(void){return _indexes == 0;}
-private: size_t _indexes;
-};
-
-/***********************************************************************
  * io impl details (internal to this file)
  * - pirate crew
  * - alignment buffer
@@ -143,24 +136,13 @@ struct usrp2_impl::io_impl{
 
     io_impl(std::vector<zero_copy_if::sptr> &dsp_xports):
         dsp_xports(dsp_xports), //the assumption is that all data transports should be identical
-        get_recv_buffs_fcn(boost::bind(&usrp2_impl::io_impl::get_recv_buffs, this, _1)),
-        get_send_buffs_fcn(boost::bind(&usrp2_impl::io_impl::get_send_buffs, this, _1)),
         async_msg_fifo(100/*messages deep*/)
     {
         for (size_t i = 0; i < dsp_xports.size(); i++){
             fc_mons.push_back(flow_control_monitor::sptr(new flow_control_monitor(
                 usrp2_impl::sram_bytes/dsp_xports.front()->get_send_frame_size()
-            )));;
+            )));
         }
-
-        //init empty packet infos
-        vrt::if_packet_info_t packet_info = vrt::if_packet_info_t();
-        packet_info.packet_count = 0xf;
-        packet_info.has_tsi = true;
-        packet_info.tsi = 0;
-        packet_info.has_tsf = true;
-        packet_info.tsf = 0;
-        prev_infos.resize(dsp_xports.size(), packet_info);
     }
 
     ~io_impl(void){
@@ -169,38 +151,27 @@ struct usrp2_impl::io_impl{
         recv_pirate_crew.join_all();
     }
 
-    bool get_send_buffs(vrt_packet_handler::managed_send_buffs_t &buffs){
-        UHD_ASSERT_THROW(send_map.size() == buffs.size());
+    managed_send_buffer::sptr get_send_buff(size_t chan, double timeout){
+        const size_t index = send_map[chan];
+        flow_control_monitor &fc_mon = *fc_mons[index];
 
-        //calculate the flow control word
-        const boost::uint32_t fc_word32 = packet_handler_send_state.next_packet_seq;
+        //wait on flow control w/ timeout
+        if (not fc_mon.check_fc_condition(timeout)) return managed_send_buffer::sptr();
 
-        //grab a managed buffer for each index
-        for (size_t i = 0; i < buffs.size(); i++){
-            if (not fc_mons[send_map[i]]->check_fc_condition(fc_word32, send_timeout)) return false;
-            buffs[i] = dsp_xports[send_map[i]]->get_send_buff(send_timeout);
-            if (not buffs[i].get()) return false;
-            buffs[i]->cast<boost::uint32_t *>()[0] = uhd::htonx(fc_word32);
-        }
-        return true;
-    }
+        //get a buffer from the transport w/ timeout
+        managed_send_buffer::sptr buff = dsp_xports[index]->get_send_buff(timeout);
+
+        //write the flow control word into the buffer
+        if (buff.get()) buff->cast<boost::uint32_t *>()[0] = uhd::htonx(fc_mon.get_curr_seq_out());
 
-    alignment_indexes indexes_to_do; //used in alignment logic
-    time_spec_t expected_time; //used in alignment logic
-    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs);
+        return buff;
+    }
 
     std::vector<zero_copy_if::sptr> &dsp_xports;
 
     //mappings from channel index to dsp xport
     std::vector<size_t> send_map, recv_map;
 
-    //timeouts set on calls to recv/send (passed into get buffs methods)
-    double recv_timeout, send_timeout;
-
-    //bound callbacks for get buffs (bound once here, not in fast-path)
-    vrt_packet_handler::get_recv_buffs_t get_recv_buffs_fcn;
-    vrt_packet_handler::get_send_buffs_t get_send_buffs_fcn;
-
     //previous state for each buffer
     std::vector<vrt::if_packet_info_t> prev_infos;
 
@@ -208,8 +179,8 @@ struct usrp2_impl::io_impl{
     std::vector<flow_control_monitor::sptr> fc_mons;
 
     //state management for the vrt packet handler code
-    vrt_packet_handler::recv_state packet_handler_recv_state;
-    vrt_packet_handler::send_state packet_handler_send_state;
+    sph::recv_packet_handler recv_handler;
+    sph::send_packet_handler send_handler;
 
     //methods and variables for the pirate crew
     void recv_pirate_loop(boost::barrier &, usrp2_mboard_impl::sptr, zero_copy_if::sptr, size_t);
@@ -258,7 +229,7 @@ void usrp2_impl::io_impl::recv_pirate_loop(
                 metadata.time_spec = time_spec_t(
                     time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), mboard->get_master_clock_freq()
                 );
-                metadata.event_code = vrt_packet_handler::get_context_code<async_metadata_t::event_code_t>(vrt_hdr, if_packet_info);
+                metadata.event_code = async_metadata_t::event_code_t(sph::get_context_code(vrt_hdr, if_packet_info));
 
                 //catch the flow control packets and react
                 if (metadata.event_code == 0){
@@ -327,8 +298,39 @@ void usrp2_impl::update_xport_channel_mapping(void){
 
     }
 
-    _io_impl->packet_handler_recv_state = vrt_packet_handler::recv_state(_io_impl->recv_map.size());
-    _io_impl->packet_handler_send_state = vrt_packet_handler::send_state(_io_impl->send_map.size());
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock recv_lock = _io_impl->recv_handler.get_scoped_lock();
+    _io_impl->recv_handler.resize(_io_impl->recv_map.size());
+    _io_impl->recv_handler.set_vrt_unpacker(&vrt::if_hdr_unpack_be);
+    _io_impl->recv_handler.set_tick_rate(_mboards.front()->get_master_clock_freq());
+    //TODO temporarily use the first dsp rate until we support non-homo rates
+    const std::string rx_dsp_name = _mboards.at(0)->get_link()[MBOARD_PROP_RX_DSP_NAMES].as<prop_names_t>().at(0);
+    const double rx_host_rate = _mboards.at(0)->get_link()[named_prop_t(MBOARD_PROP_RX_DSP, rx_dsp_name)][DSP_PROP_HOST_RATE].as<double>();
+    _io_impl->recv_handler.set_samp_rate(rx_host_rate);
+    for (size_t chan = 0; chan < _io_impl->recv_handler.size(); chan++){
+        _io_impl->recv_handler.set_xport_chan_get_buff(chan, boost::bind(
+            &uhd::transport::zero_copy_if::get_recv_buff,
+            _io_impl->dsp_xports[_io_impl->recv_map[chan]], _1
+        ));
+    }
+    _io_impl->recv_handler.set_converter(_rx_otw_type);
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock send_lock = _io_impl->send_handler.get_scoped_lock();
+    _io_impl->send_handler.resize(_io_impl->send_map.size());
+    _io_impl->send_handler.set_vrt_packer(&vrt::if_hdr_pack_be, vrt_send_header_offset_words32);
+    _io_impl->send_handler.set_tick_rate(_mboards.front()->get_master_clock_freq());
+    //TODO temporarily use the first dsp rate until we support non-homo rates
+    const std::string tx_dsp_name = _mboards.at(0)->get_link()[MBOARD_PROP_TX_DSP_NAMES].as<prop_names_t>().at(0);
+    const double tx_host_rate = _mboards.at(0)->get_link()[named_prop_t(MBOARD_PROP_TX_DSP, tx_dsp_name)][DSP_PROP_HOST_RATE].as<double>();
+    _io_impl->send_handler.set_samp_rate(tx_host_rate);
+    for (size_t chan = 0; chan < _io_impl->send_handler.size(); chan++){
+        _io_impl->send_handler.set_xport_chan_get_buff(chan, boost::bind(
+            &usrp2_impl::io_impl::get_send_buff, _io_impl.get(), chan, _1
+        ));
+    }
+    _io_impl->send_handler.set_converter(_tx_otw_type);
+    _io_impl->send_handler.set_max_samples_per_packet(get_max_send_samps_per_packet());
 }
 
 /***********************************************************************
@@ -355,143 +357,17 @@ size_t usrp2_impl::get_max_send_samps_per_packet(void) const{
 }
 
 size_t usrp2_impl::send(
-    const send_buffs_type &buffs, size_t num_samps,
+    const send_buffs_type &buffs, size_t nsamps_per_buff,
     const tx_metadata_t &metadata, const io_type_t &io_type,
     send_mode_t send_mode, double timeout
 ){
-    _io_impl->send_timeout = timeout;
-    return vrt_packet_handler::send(
-        _io_impl->packet_handler_send_state,       //last state of the send handler
-        buffs, num_samps,                          //buffer to fill
-        metadata, send_mode,                       //samples metadata
-        io_type, _tx_otw_type,                     //input and output types to convert
-        _mboards.front()->get_master_clock_freq(), //master clock tick rate
-        uhd::transport::vrt::if_hdr_pack_be,
-        _io_impl->get_send_buffs_fcn,
-        get_max_send_samps_per_packet(),
-        vrt_send_header_offset_words32
-    );
-}
-
-/***********************************************************************
- * Alignment logic on receive
- **********************************************************************/
-static UHD_INLINE time_spec_t extract_time_spec(
-    const vrt::if_packet_info_t &packet_info
-){
-    return time_spec_t( //assumes has_tsi and has_tsf are true
-        time_t(packet_info.tsi), size_t(packet_info.tsf),
-        100e6 //tick rate does not have to be correct for comparison purposes
+    return _io_impl->send_handler.send(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        send_mode, timeout
     );
 }
 
-static UHD_INLINE void extract_packet_info(
-    managed_recv_buffer::sptr &buff,
-    vrt::if_packet_info_t &prev_info,
-    time_spec_t &time, bool &clear, bool &msg
-){
-    //extract packet info
-    vrt::if_packet_info_t next_info;
-    next_info.num_packet_words32 = buff->size()/sizeof(boost::uint32_t);
-    vrt::if_hdr_unpack_be(buff->cast<const boost::uint32_t *>(), next_info);
-
-    //handle the packet count / sequence number
-    if ((prev_info.packet_count+1)%16 != next_info.packet_count){
-        UHD_MSG(fastpath) << "O"; //report overflow (drops in the kernel)
-    }
-
-    time = extract_time_spec(next_info);
-    clear = extract_time_spec(prev_info) > time;
-    msg = next_info.packet_type != vrt::if_packet_info_t::PACKET_TYPE_DATA;
-    prev_info = next_info;
-}
-
-static UHD_INLINE bool handle_msg_packet(
-    vrt_packet_handler::managed_recv_buffs_t &buffs, size_t index
-){
-    for (size_t i = 0; i < buffs.size(); i++){
-        if (i == index) continue;
-        buffs[i].reset(); //set NULL
-    }
-    return true;
-}
-
-UHD_INLINE bool usrp2_impl::io_impl::get_recv_buffs(
-    vrt_packet_handler::managed_recv_buffs_t &buffs
-){
-    if (buffs.size() == 1){
-        buffs[0] = dsp_xports[recv_map[0]]->get_recv_buff(recv_timeout);
-        if (buffs[0].get() == NULL) return false;
-        bool clear, msg; time_spec_t time; //unused variables
-        //call extract_packet_info to handle printing the overflows
-        extract_packet_info(buffs[0], this->prev_infos[recv_map[0]], time, clear, msg);
-        return true;
-    }
-    //-------------------- begin alignment logic ---------------------//
-    UHD_ASSERT_THROW(recv_map.size() == buffs.size());
-    boost::system_time exit_time = boost::get_system_time() + to_time_dur(recv_timeout);
-    managed_recv_buffer::sptr buff_tmp;
-    bool clear, msg;
-    size_t index;
-
-    //If we did not enter this routine with an empty indexes set,
-    //jump to after the clear so we can preserve the previous state.
-    //This saves buffers from being lost when using non-blocking recv.
-    if (not indexes_to_do.empty()) goto skip_pop_initial;
-
-    //respond to a clear by starting from scratch
-    got_clear:
-    indexes_to_do.reset(buffs.size());
-    clear = false;
-
-    //do an initial pop to load an initial sequence id
-    index = indexes_to_do.front();
-    buff_tmp = dsp_xports[recv_map[index]]->get_recv_buff(from_time_dur(exit_time - boost::get_system_time()));
-    if (buff_tmp.get() == NULL) return false;
-    extract_packet_info(buff_tmp, this->prev_infos[recv_map[index]], expected_time, clear, msg);
-    if (clear) goto got_clear;
-    buffs[index] = buff_tmp;
-    if (msg) return handle_msg_packet(buffs, index);
-    indexes_to_do.remove(index);
-    skip_pop_initial:
-
-    //get an aligned set of elements from the buffers:
-    while(not indexes_to_do.empty()){
-
-        //pop an element off for this index
-        index = indexes_to_do.front();
-        buff_tmp = dsp_xports[recv_map[index]]->get_recv_buff(from_time_dur(exit_time - boost::get_system_time()));
-        if (buff_tmp.get() == NULL) return false;
-        time_spec_t this_time;
-        extract_packet_info(buff_tmp, this->prev_infos[recv_map[index]], this_time, clear, msg);
-        if (clear) goto got_clear;
-        buffs[index] = buff_tmp;
-        if (msg) return handle_msg_packet(buffs, index);
-
-        //if the sequence id matches:
-        //  remove this index from the list and continue
-        if (this_time == expected_time){
-            indexes_to_do.remove(index);
-        }
-
-        //if the sequence id is newer:
-        //  use the new expected time for comparison
-        //  add all other indexes back into the list
-        else if (this_time > expected_time){
-            expected_time = this_time;
-            indexes_to_do.reset(buffs.size());
-            indexes_to_do.remove(index);
-        }
-
-        //if the sequence id is older:
-        //  continue with the same index to try again
-        //else if (this_time < expected_time)...
-
-    }
-    return true;
-    //-------------------- end alignment logic -----------------------//
-}
-
 /***********************************************************************
  * Receive Data
  **********************************************************************/
@@ -505,26 +381,14 @@ size_t usrp2_impl::get_max_recv_samps_per_packet(void) const{
     return bpp/_rx_otw_type.get_sample_size();
 }
 
-void usrp2_impl::handle_overflow(size_t chan){
-    UHD_MSG(fastpath) << "O";
-    ldiv_t indexes = ldiv(chan, usrp2_mboard_impl::NUM_RX_DSPS);
-    _mboards.at(indexes.quot)->handle_overflow(indexes.rem);
-}
-
 size_t usrp2_impl::recv(
-    const recv_buffs_type &buffs, size_t num_samps,
+    const recv_buffs_type &buffs, size_t nsamps_per_buff,
     rx_metadata_t &metadata, const io_type_t &io_type,
     recv_mode_t recv_mode, double timeout
 ){
-    _io_impl->recv_timeout = timeout;
-    return vrt_packet_handler::recv(
-        _io_impl->packet_handler_recv_state,       //last state of the recv handler
-        buffs, num_samps,                          //buffer to fill
-        metadata, recv_mode,                       //samples metadata
-        io_type, _rx_otw_type,                     //input and output types to convert
-        _mboards.front()->get_master_clock_freq(), //master clock tick rate
-        uhd::transport::vrt::if_hdr_unpack_be,
-        _io_impl->get_recv_buffs_fcn,
-        boost::bind(&usrp2_impl::handle_overflow, this, _1)
+    return _io_impl->recv_handler.recv(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        recv_mode, timeout
     );
 }
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index 4a28ea9c4..6bf412a3e 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -466,6 +466,7 @@ void usrp2_mboard_impl::set(const wax::obj &key, const wax::obj &val){
 
     case MBOARD_PROP_CLOCK_RATE:
         UHD_ASSERT_THROW(val.as<double>() == this->get_master_clock_freq());
+        _device.update_xport_channel_mapping();
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
diff --git a/host/lib/usrp/usrp2/usrp2_impl.hpp b/host/lib/usrp/usrp2/usrp2_impl.hpp
index ccaf0c9a8..4d19863b1 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.hpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.hpp
@@ -220,7 +220,6 @@ private:
     uhd::otw_type_t _rx_otw_type, _tx_otw_type;
     UHD_PIMPL_DECL(io_impl) _io_impl;
     void io_init(void);
-    void handle_overflow(size_t);
 };
 
 #endif /* INCLUDED_USRP2_IMPL_HPP */
diff --git a/host/lib/usrp/usrp_e100/dsp_impl.cpp b/host/lib/usrp/usrp_e100/dsp_impl.cpp
index 8d084f066..93034b5dc 100644
--- a/host/lib/usrp/usrp_e100/dsp_impl.cpp
+++ b/host/lib/usrp/usrp_e100/dsp_impl.cpp
@@ -104,6 +104,7 @@ void usrp_e100_impl::rx_ddc_set(const wax::obj &key_, const wax::obj &val){
                 dsp_type1::calc_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq)
             );
         }
+        this->update_xport_channel_mapping(); //rate changed -> update
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
@@ -181,6 +182,7 @@ void usrp_e100_impl::tx_duc_set(const wax::obj &key_, const wax::obj &val){
             //set the scaling
             _iface->poke32(UE_REG_DSP_TX_SCALE_IQ, dsp_type1::calc_iq_scale_word(_duc_interp));
         }
+        this->update_xport_channel_mapping(); //rate changed -> update
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
diff --git a/host/lib/usrp/usrp_e100/io_impl.cpp b/host/lib/usrp/usrp_e100/io_impl.cpp
index aa6e7c485..91b129276 100644
--- a/host/lib/usrp/usrp_e100/io_impl.cpp
+++ b/host/lib/usrp/usrp_e100/io_impl.cpp
@@ -15,14 +15,16 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
+#include "../../transport/super_recv_packet_handler.hpp"
+#include "../../transport/super_send_packet_handler.hpp"
 #include "usrp_e100_impl.hpp"
 #include "usrp_e100_regs.hpp"
 #include <uhd/utils/msg.hpp>
 #include <uhd/utils/log.hpp>
 #include <uhd/usrp/dsp_utils.hpp>
+#include <uhd/usrp/dsp_props.hpp>
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/transport/bounded_buffer.hpp>
-#include "../../transport/vrt_packet_handler.hpp"
 #include <boost/bind.hpp>
 #include <boost/format.hpp>
 #include <boost/thread/thread.hpp>
@@ -51,8 +53,6 @@ static const int underflow_flags = async_metadata_t::EVENT_CODE_UNDERFLOW | asyn
 struct usrp_e100_impl::io_impl{
     io_impl(zero_copy_if::sptr &xport):
         data_xport(xport),
-        get_recv_buffs_fcn(boost::bind(&usrp_e100_impl::io_impl::get_recv_buffs, this, _1)),
-        get_send_buffs_fcn(boost::bind(&usrp_e100_impl::io_impl::get_send_buffs, this, _1)),
         recv_pirate_booty(data_xport->get_num_recv_frames()),
         async_msg_fifo(100/*messages deep*/)
     {
@@ -65,16 +65,11 @@ struct usrp_e100_impl::io_impl{
         recv_pirate_crew.join_all();
     }
 
-    bool get_recv_buffs(vrt_packet_handler::managed_recv_buffs_t &buffs){
-        UHD_ASSERT_THROW(buffs.size() == 1);
+    managed_recv_buffer::sptr get_recv_buff(double timeout){
         boost::this_thread::disable_interruption di; //disable because the wait can throw
-        return recv_pirate_booty.pop_with_timed_wait(buffs.front(), recv_timeout);
-    }
-
-    bool get_send_buffs(vrt_packet_handler::managed_send_buffs_t &buffs){
-        UHD_ASSERT_THROW(buffs.size() == 1);
-        buffs[0] = data_xport->get_send_buff(send_timeout);
-        return buffs[0].get() != NULL;
+        managed_recv_buffer::sptr buff;
+        recv_pirate_booty.pop_with_timed_wait(buff, timeout);
+        return buff; //ASSUME buff == NULL when pop times-out
     }
 
     //The data transport is listed first so that it is deconstructed last,
@@ -82,16 +77,9 @@ struct usrp_e100_impl::io_impl{
     //This comment is invalid because its now a reference and not stored here.
     zero_copy_if::sptr &data_xport;
 
-    //bound callbacks for get buffs (bound once here, not in fast-path)
-    vrt_packet_handler::get_recv_buffs_t get_recv_buffs_fcn;
-    vrt_packet_handler::get_send_buffs_t get_send_buffs_fcn;
-
-    //timeouts set on calls to recv/send (passed into get buffs methods)
-    double recv_timeout, send_timeout;
-
     //state management for the vrt packet handler code
-    vrt_packet_handler::recv_state packet_handler_recv_state;
-    vrt_packet_handler::send_state packet_handler_send_state;
+    sph::recv_packet_handler recv_handler;
+    sph::send_packet_handler send_handler;
     bool continuous_streaming;
 
     //a pirate's life is the life for me!
@@ -133,16 +121,18 @@ void usrp_e100_impl::io_impl::recv_pirate_loop(
             vrt::if_packet_info_t if_packet_info;
             if_packet_info.num_packet_words32 = buff->size()/sizeof(boost::uint32_t);
             const boost::uint32_t *vrt_hdr = buff->cast<const boost::uint32_t *>();
-            vrt::if_hdr_unpack_le(vrt_hdr, if_packet_info);
 
             //handle an rx data packet or inline message
-            if (if_packet_info.sid == rx_data_inline_sid){
+            if (uhd::ntohx(vrt_hdr[1]) == rx_data_inline_sid){ //ASSUME has_sid
                 if (fp_recv_debug) UHD_LOGV(always) << "this is rx_data_inline_sid\n";
                 //same number of frames as the data transport -> always immediate
                 recv_pirate_booty.push_with_wait(buff);
                 continue;
             }
 
+            //unpack the vrt header and process below...
+            vrt::if_hdr_unpack_le(vrt_hdr, if_packet_info);
+
             //handle a tx async report message
             if (if_packet_info.sid == tx_async_report_sid and if_packet_info.packet_type != vrt::if_packet_info_t::PACKET_TYPE_DATA){
                 if (fp_recv_debug) UHD_LOGV(always) << "this is tx_async_report_sid\n";
@@ -154,7 +144,7 @@ void usrp_e100_impl::io_impl::recv_pirate_loop(
                 metadata.time_spec = time_spec_t(
                     time_t(if_packet_info.tsi), size_t(if_packet_info.tsf), clock_ctrl->get_fpga_clock_rate()
                 );
-                metadata.event_code = vrt_packet_handler::get_context_code<async_metadata_t::event_code_t>(vrt_hdr, if_packet_info);
+                metadata.event_code = async_metadata_t::event_code_t(sph::get_context_code(vrt_hdr, if_packet_info));
 
                 //print the famous U, and push the metadata into the message queue
                 if (metadata.event_code & underflow_flags) UHD_MSG(fastpath) << "U";
@@ -162,6 +152,7 @@ void usrp_e100_impl::io_impl::recv_pirate_loop(
                 continue;
             }
 
+            //TODO replace this below with a UHD_MSG(error)
             if (fp_recv_debug) UHD_LOGV(always) << "this is unknown packet\n";
 
         }catch(const std::exception &e){
@@ -213,6 +204,42 @@ void usrp_e100_impl::io_init(void){
         boost::ref(spawn_barrier), _clock_ctrl
     ));
     spawn_barrier.wait();
+    //update mapping here since it didnt b4 when io init not called first
+    update_xport_channel_mapping();
+}
+
+void usrp_e100_impl::update_xport_channel_mapping(void){
+    if (_io_impl.get() == NULL) return; //not inited yet
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock recv_lock = _io_impl->recv_handler.get_scoped_lock();
+    _io_impl->recv_handler.resize(_rx_subdev_spec.size());
+    _io_impl->recv_handler.set_vrt_unpacker(&vrt::if_hdr_unpack_le);
+    _io_impl->recv_handler.set_tick_rate(_clock_ctrl->get_fpga_clock_rate());
+    _io_impl->recv_handler.set_samp_rate(_rx_ddc_proxy->get_link()[DSP_PROP_HOST_RATE].as<double>());
+    for (size_t chan = 0; chan < _io_impl->recv_handler.size(); chan++){
+        _io_impl->recv_handler.set_xport_chan_get_buff(chan, boost::bind(
+            &usrp_e100_impl::io_impl::get_recv_buff, _io_impl.get(), _1
+        ));
+        _io_impl->recv_handler.set_overflow_handler(chan, boost::bind(
+            &usrp_e100_impl::handle_overrun, this, chan
+        ));
+    }
+    _io_impl->recv_handler.set_converter(_recv_otw_type);
+
+    //set all of the relevant properties on the handler
+    boost::mutex::scoped_lock send_lock = _io_impl->send_handler.get_scoped_lock();
+    _io_impl->send_handler.resize(_tx_subdev_spec.size());
+    _io_impl->send_handler.set_vrt_packer(&vrt::if_hdr_pack_le);
+    _io_impl->send_handler.set_tick_rate(_clock_ctrl->get_fpga_clock_rate());
+    _io_impl->send_handler.set_samp_rate(_tx_duc_proxy->get_link()[DSP_PROP_HOST_RATE].as<double>());
+    for (size_t chan = 0; chan < _io_impl->send_handler.size(); chan++){
+        _io_impl->send_handler.set_xport_chan_get_buff(chan, boost::bind(
+            &uhd::transport::zero_copy_if::get_send_buff, _io_impl->data_xport, _1
+        ));
+    }
+    _io_impl->send_handler.set_converter(_send_otw_type);
+    _io_impl->send_handler.set_max_samples_per_packet(get_max_send_samps_per_packet());
 }
 
 void usrp_e100_impl::issue_stream_cmd(const stream_cmd_t &stream_cmd){
@@ -222,8 +249,7 @@ void usrp_e100_impl::issue_stream_cmd(const stream_cmd_t &stream_cmd){
     _iface->poke32(UE_REG_CTRL_RX_TIME_TICKS, stream_cmd.time_spec.get_tick_count(_clock_ctrl->get_fpga_clock_rate()));
 }
 
-void usrp_e100_impl::handle_overrun(size_t){
-    UHD_MSG(fastpath) << "O"; //the famous OOOOOOOOOOO
+void usrp_e100_impl::handle_overrun(size_t /*chan*/){
     if (_io_impl->continuous_streaming){
         this->issue_stream_cmd(stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
     }
@@ -242,20 +268,14 @@ size_t usrp_e100_impl::get_max_send_samps_per_packet(void) const{
 }
 
 size_t usrp_e100_impl::send(
-    const send_buffs_type &buffs, size_t num_samps,
+    const send_buffs_type &buffs, size_t nsamps_per_buff,
     const tx_metadata_t &metadata, const io_type_t &io_type,
     send_mode_t send_mode, double timeout
 ){
-    _io_impl->send_timeout = timeout;
-    return vrt_packet_handler::send(
-        _io_impl->packet_handler_send_state,       //last state of the send handler
-        buffs, num_samps,                          //buffer to fill
-        metadata, send_mode,                       //samples metadata
-        io_type, _send_otw_type,                   //input and output types to convert
-        _clock_ctrl->get_fpga_clock_rate(),        //master clock tick rate
-        uhd::transport::vrt::if_hdr_pack_le,
-        _io_impl->get_send_buffs_fcn,
-        get_max_send_samps_per_packet()
+    return _io_impl->send_handler.send(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        send_mode, timeout
     );
 }
 
@@ -273,20 +293,14 @@ size_t usrp_e100_impl::get_max_recv_samps_per_packet(void) const{
 }
 
 size_t usrp_e100_impl::recv(
-    const recv_buffs_type &buffs, size_t num_samps,
+    const recv_buffs_type &buffs, size_t nsamps_per_buff,
     rx_metadata_t &metadata, const io_type_t &io_type,
     recv_mode_t recv_mode, double timeout
 ){
-    _io_impl->recv_timeout = timeout;
-    return vrt_packet_handler::recv(
-        _io_impl->packet_handler_recv_state,       //last state of the recv handler
-        buffs, num_samps,                          //buffer to fill
-        metadata, recv_mode,                       //samples metadata
-        io_type, _recv_otw_type,                   //input and output types to convert
-        _clock_ctrl->get_fpga_clock_rate(),        //master clock tick rate
-        uhd::transport::vrt::if_hdr_unpack_le,
-        _io_impl->get_recv_buffs_fcn,
-        boost::bind(&usrp_e100_impl::handle_overrun, this, _1)
+    return _io_impl->recv_handler.recv(
+        buffs, nsamps_per_buff,
+        metadata, io_type,
+        recv_mode, timeout
     );
 }
 
diff --git a/host/lib/usrp/usrp_e100/mboard_impl.cpp b/host/lib/usrp/usrp_e100/mboard_impl.cpp
index 483286e47..f4b8d79f6 100644
--- a/host/lib/usrp/usrp_e100/mboard_impl.cpp
+++ b/host/lib/usrp/usrp_e100/mboard_impl.cpp
@@ -214,6 +214,7 @@ void usrp_e100_impl::mboard_set(const wax::obj &key, const wax::obj &val){
             << "See the application notes for USRP-E1XX for further instructions.\n"
         ;
         _clock_ctrl->set_fpga_clock_rate(val.as<double>());
+        this->update_xport_channel_mapping();
         return;
 
     default: UHD_THROW_PROP_SET_ERROR();
diff --git a/host/lib/usrp/usrp_e100/usrp_e100_impl.cpp b/host/lib/usrp/usrp_e100/usrp_e100_impl.cpp
index e9e9b6e20..5b039aafc 100644
--- a/host/lib/usrp/usrp_e100/usrp_e100_impl.cpp
+++ b/host/lib/usrp/usrp_e100/usrp_e100_impl.cpp
@@ -39,7 +39,7 @@ static device_addrs_t usrp_e100_find(const device_addr_t &hint){
     device_addrs_t usrp_e100_addrs;
 
     //return an empty list of addresses when type is set to non-usrp-e
-    if (hint.has_key("type") and hint["type"] != "usrp-e") return usrp_e100_addrs;
+    if (hint.has_key("type") and hint["type"] != "e100") return usrp_e100_addrs;
 
     //device node not provided, assume its 0
     if (not hint.has_key("node")){
@@ -171,12 +171,13 @@ usrp_e100_impl::usrp_e100_impl(
     //init the codec properties
     codec_init();
 
-    //init the io send/recv
-    io_init();
-
     //set default subdev specs
     this->mboard_set(MBOARD_PROP_RX_SUBDEV_SPEC, subdev_spec_t());
     this->mboard_set(MBOARD_PROP_TX_SUBDEV_SPEC, subdev_spec_t());
+
+    //init the io send/recv
+    io_init();
+
 }
 
 usrp_e100_impl::~usrp_e100_impl(void){
diff --git a/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp b/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp
index 318a75191..1c17863fb 100644
--- a/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp
+++ b/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp
@@ -104,6 +104,7 @@ private:
     void io_init(void);
     void issue_stream_cmd(const uhd::stream_cmd_t &stream_cmd);
     void handle_overrun(size_t);
+    void update_xport_channel_mapping(void);
 
     //configuration shadows
     uhd::clock_config_t _clock_config;
diff --git a/host/tests/CMakeLists.txt b/host/tests/CMakeLists.txt
index b38afccf0..b7bcfb7d5 100644
--- a/host/tests/CMakeLists.txt
+++ b/host/tests/CMakeLists.txt
@@ -28,6 +28,8 @@ SET(test_sources
     gain_group_test.cpp
     msg_test.cpp
     ranges_test.cpp
+    sph_recv_test.cpp
+    sph_send_test.cpp
     subdev_spec_test.cpp
     time_spec_test.cpp
     tune_helper_test.cpp
diff --git a/host/tests/convert_test.cpp b/host/tests/convert_test.cpp
index d1c2b7625..d828ed64a 100644
--- a/host/tests/convert_test.cpp
+++ b/host/tests/convert_test.cpp
@@ -31,7 +31,7 @@ typedef std::complex<boost::int16_t> sc16_t;
 typedef std::complex<float> fc32_t;
 typedef std::complex<double> fc64_t;
 
-#define MY_CHECK_CLOSE(a, b, f) if ((std::abs(a) > (f) and std::abs(b) > (f))) \
+#define MY_CHECK_CLOSE(a, b, f) if ((std::abs(a) > (f))) \
     BOOST_CHECK_CLOSE_FRACTION(a, b, f)
 
 /***********************************************************************
@@ -55,12 +55,12 @@ template <typename Range> static void loopback(
     //convert to intermediate type
     convert::get_converter_cpu_to_otw(
         io_type, otw_type, input0.size(), output0.size()
-    )(input0, output0, nsamps);
+    )(input0, output0, nsamps, 32767.);
 
     //convert back to host type
     convert::get_converter_otw_to_cpu(
         io_type, otw_type, input1.size(), output1.size()
-    )(input1, output1, nsamps);
+    )(input1, output1, nsamps, 1/32767.);
 }
 
 /***********************************************************************
@@ -207,12 +207,12 @@ BOOST_AUTO_TEST_CASE(test_convert_types_fc32_to_sc16){
     //convert float to intermediate
     convert::get_converter_cpu_to_otw(
         io_type_in, otw_type, input0.size(), output0.size()
-    )(input0, output0, nsamps);
+    )(input0, output0, nsamps, 32767.);
 
     //convert intermediate to short
     convert::get_converter_otw_to_cpu(
         io_type_out, otw_type, input1.size(), output1.size()
-    )(input1, output1, nsamps);
+    )(input1, output1, nsamps, 1/32767.);
 
     //test that the inputs and outputs match
     for (size_t i = 0; i < nsamps; i++){
@@ -247,12 +247,12 @@ BOOST_AUTO_TEST_CASE(test_convert_types_sc16_to_fc32){
     //convert short to intermediate
     convert::get_converter_cpu_to_otw(
         io_type_in, otw_type, input0.size(), output0.size()
-    )(input0, output0, nsamps);
+    )(input0, output0, nsamps, 32767.);
 
     //convert intermediate to float
     convert::get_converter_otw_to_cpu(
         io_type_out, otw_type, input1.size(), output1.size()
-    )(input1, output1, nsamps);
+    )(input1, output1, nsamps, 1/32767.);
 
     //test that the inputs and outputs match
     for (size_t i = 0; i < nsamps; i++){
diff --git a/host/tests/sph_recv_test.cpp b/host/tests/sph_recv_test.cpp
new file mode 100644
index 000000000..6bb5d1175
--- /dev/null
+++ b/host/tests/sph_recv_test.cpp
@@ -0,0 +1,715 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <boost/test/unit_test.hpp>
+#include "../lib/transport/super_recv_packet_handler.hpp"
+#include <boost/shared_array.hpp>
+#include <boost/bind.hpp>
+#include <complex>
+#include <vector>
+#include <list>
+
+#define BOOST_CHECK_TS_CLOSE(a, b) \
+    BOOST_CHECK_CLOSE((a).get_real_secs(), (b).get_real_secs(), 0.001)
+
+/***********************************************************************
+ * A dummy managed receive buffer for testing
+ **********************************************************************/
+class dummy_mrb : public uhd::transport::managed_recv_buffer{
+public:
+    void release(void){
+        //NOP
+    }
+
+    sptr get_new(boost::shared_array<char> mem, size_t len){
+        _mem = mem;
+        _len = len;
+        return make_managed_buffer(this);
+    }
+
+private:
+    const void *get_buff(void) const{return _mem.get();}
+    size_t get_size(void) const{return _len;}
+
+    boost::shared_array<char> _mem;
+    size_t _len;
+};
+
+/***********************************************************************
+ * A dummy transport class to fill with fake data
+ **********************************************************************/
+class dummy_recv_xport_class{
+public:
+    dummy_recv_xport_class(const uhd::otw_type_t &otw_type){
+        _otw_type = otw_type;
+    }
+
+    void push_back_packet(
+        uhd::transport::vrt::if_packet_info_t &ifpi,
+        const boost::uint32_t optional_msg_word = 0
+    ){
+        const size_t max_pkt_len = (ifpi.num_payload_words32 + uhd::transport::vrt::max_if_hdr_words32 + 1/*tlr*/)*sizeof(boost::uint32_t);
+        _mems.push_back(boost::shared_array<char>(new char[max_pkt_len]));
+        if (_otw_type.byteorder == uhd::otw_type_t::BO_BIG_ENDIAN){
+            uhd::transport::vrt::if_hdr_pack_be(reinterpret_cast<boost::uint32_t *>(_mems.back().get()), ifpi);
+        }
+        if (_otw_type.byteorder == uhd::otw_type_t::BO_LITTLE_ENDIAN){
+            uhd::transport::vrt::if_hdr_pack_le(reinterpret_cast<boost::uint32_t *>(_mems.back().get()), ifpi);
+        }
+        (reinterpret_cast<boost::uint32_t *>(_mems.back().get()) + ifpi.num_header_words32)[0] = optional_msg_word | uhd::byteswap(optional_msg_word);
+        _lens.push_back(ifpi.num_packet_words32*sizeof(boost::uint32_t));
+    }
+
+    uhd::transport::managed_recv_buffer::sptr get_recv_buff(double){
+        if (_mems.empty()) return uhd::transport::managed_recv_buffer::sptr(); //timeout
+        _mrbs.push_back(dummy_mrb());
+        uhd::transport::managed_recv_buffer::sptr mrb = _mrbs.back().get_new(_mems.front(), _lens.front());
+        _mems.pop_front();
+        _lens.pop_front();
+        return mrb;
+    }
+
+private:
+    std::list<boost::shared_array<char> > _mems;
+    std::list<size_t> _lens;
+    std::list<dummy_mrb> _mrbs; //list means no-realloc
+    uhd::otw_type_t _otw_type;
+};
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_one_channel_normal){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    dummy_recv_xport_class dummy_recv_xport(otw_type);
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        dummy_recv_xport.push_back_packet(ifpi);
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(1);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    handler.set_xport_chan_get_buff(0, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xport, _1));
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > buff(20);
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            &buff.front(), buff.size(), metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+        BOOST_CHECK(not metadata.more_fragments);
+        BOOST_CHECK(metadata.has_time_spec);
+        BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        BOOST_CHECK_EQUAL(num_samps_ret, 10 + i%10);
+        num_accum_samps += num_samps_ret;
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            &buff.front(), buff.size(), metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_one_channel_sequence_error){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    dummy_recv_xport_class dummy_recv_xport(otw_type);
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        if (i != NUM_PKTS_TO_TEST/2){ //simulate a lost packet
+            dummy_recv_xport.push_back_packet(ifpi);
+        }
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(1);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    handler.set_xport_chan_get_buff(0, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xport, _1));
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > buff(20);
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            &buff.front(), buff.size(), metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        if (i == NUM_PKTS_TO_TEST/2){
+            //must get the soft overflow here
+            BOOST_REQUIRE(metadata.error_code == uhd::rx_metadata_t::ERROR_CODE_OVERFLOW);
+            BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+            num_accum_samps += 10 + i%10;
+        }
+        else{
+            BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+            BOOST_CHECK(not metadata.more_fragments);
+            BOOST_CHECK(metadata.has_time_spec);
+            BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+            BOOST_CHECK_EQUAL(num_samps_ret, 10 + i%10);
+            num_accum_samps += num_samps_ret;
+        }
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            &buff.front(), buff.size(), metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_one_channel_inline_message){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    dummy_recv_xport_class dummy_recv_xport(otw_type);
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        dummy_recv_xport.push_back_packet(ifpi);
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+
+        //simulate overflow
+        if (i == NUM_PKTS_TO_TEST/2){
+            ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_EXTENSION;
+            ifpi.num_payload_words32 = 1;
+            dummy_recv_xport.push_back_packet(ifpi, uhd::rx_metadata_t::ERROR_CODE_OVERFLOW);
+            ifpi.packet_count++;
+            ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+        }
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(1);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    handler.set_xport_chan_get_buff(0, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xport, _1));
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > buff(20);
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            &buff.front(), buff.size(), metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+        BOOST_CHECK(not metadata.more_fragments);
+        BOOST_CHECK(metadata.has_time_spec);
+        BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        BOOST_CHECK_EQUAL(num_samps_ret, 10 + i%10);
+        num_accum_samps += num_samps_ret;
+        if (i == NUM_PKTS_TO_TEST/2){
+            handler.recv(
+                &buff.front(), buff.size(), metadata,
+                uhd::io_type_t::COMPLEX_FLOAT32,
+                uhd::device::RECV_MODE_ONE_PACKET, 1.0
+            );
+            std::cout << "metadata.error_code " << metadata.error_code << std::endl;
+            BOOST_REQUIRE(metadata.error_code == uhd::rx_metadata_t::ERROR_CODE_OVERFLOW);
+            BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        }
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            &buff.front(), buff.size(), metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_multi_channel_normal){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+    static const size_t NUM_SAMPS_PER_BUFF = 20;
+    static const size_t NCHANNELS = 4;
+
+    std::vector<dummy_recv_xport_class> dummy_recv_xports(NCHANNELS, dummy_recv_xport_class(otw_type));
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        for (size_t ch = 0; ch < NCHANNELS; ch++){
+            dummy_recv_xports[ch].push_back_packet(ifpi);
+        }
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(NCHANNELS);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        handler.set_xport_chan_get_buff(ch, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xports[ch], _1));
+    }
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > mem(NUM_SAMPS_PER_BUFF*NCHANNELS);
+    std::vector<std::complex<float> *> buffs(NCHANNELS);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        buffs[ch] = &mem[ch*NUM_SAMPS_PER_BUFF];
+    }
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+        BOOST_CHECK(not metadata.more_fragments);
+        BOOST_CHECK(metadata.has_time_spec);
+        BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        BOOST_CHECK_EQUAL(num_samps_ret, 10 + i%10);
+        num_accum_samps += num_samps_ret;
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_multi_channel_sequence_error){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+    static const size_t NUM_SAMPS_PER_BUFF = 20;
+    static const size_t NCHANNELS = 4;
+
+    std::vector<dummy_recv_xport_class> dummy_recv_xports(NCHANNELS, dummy_recv_xport_class(otw_type));
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        for (size_t ch = 0; ch < NCHANNELS; ch++){
+            if (i == NUM_PKTS_TO_TEST/2 and ch == 2){
+                continue; //simulates a lost packet
+            }
+            dummy_recv_xports[ch].push_back_packet(ifpi);
+        }
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(NCHANNELS);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        handler.set_xport_chan_get_buff(ch, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xports[ch], _1));
+    }
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > mem(NUM_SAMPS_PER_BUFF*NCHANNELS);
+    std::vector<std::complex<float> *> buffs(NCHANNELS);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        buffs[ch] = &mem[ch*NUM_SAMPS_PER_BUFF];
+    }
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        if (i == NUM_PKTS_TO_TEST/2){
+            //must get the soft overflow here
+            BOOST_REQUIRE(metadata.error_code == uhd::rx_metadata_t::ERROR_CODE_OVERFLOW);
+            BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+            num_accum_samps += 10 + i%10;
+        }
+        else{
+            BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+            BOOST_CHECK(not metadata.more_fragments);
+            BOOST_CHECK(metadata.has_time_spec);
+            BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+            BOOST_CHECK_EQUAL(num_samps_ret, 10 + i%10);
+            num_accum_samps += num_samps_ret;
+        }
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_multi_channel_time_error){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+    static const size_t NUM_SAMPS_PER_BUFF = 20;
+    static const size_t NCHANNELS = 4;
+
+    std::vector<dummy_recv_xport_class> dummy_recv_xports(NCHANNELS, dummy_recv_xport_class(otw_type));
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        for (size_t ch = 0; ch < NCHANNELS; ch++){
+            dummy_recv_xports[ch].push_back_packet(ifpi);
+        }
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+        if (i == NUM_PKTS_TO_TEST/2){
+            ifpi.tsf = 0; //simulate the user changing the time
+        }
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(NCHANNELS);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        handler.set_xport_chan_get_buff(ch, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xports[ch], _1));
+    }
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > mem(NUM_SAMPS_PER_BUFF*NCHANNELS);
+    std::vector<std::complex<float> *> buffs(NCHANNELS);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        buffs[ch] = &mem[ch*NUM_SAMPS_PER_BUFF];
+    }
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+        BOOST_CHECK(not metadata.more_fragments);
+        BOOST_CHECK(metadata.has_time_spec);
+        BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        BOOST_CHECK_EQUAL(num_samps_ret, 10 + i%10);
+        num_accum_samps += num_samps_ret;
+        if (i == NUM_PKTS_TO_TEST/2){
+            num_accum_samps = 0; //simulate the user changing the time
+        }
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_recv_multi_channel_fragment){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    ifpi.packet_type = uhd::transport::vrt::if_packet_info_t::PACKET_TYPE_DATA;
+    ifpi.num_payload_words32 = 0;
+    ifpi.packet_count = 0;
+    ifpi.sob = true;
+    ifpi.eob = false;
+    ifpi.has_sid = false;
+    ifpi.has_cid = false;
+    ifpi.has_tsi = true;
+    ifpi.has_tsf = true;
+    ifpi.tsi = 0;
+    ifpi.tsf = 0;
+    ifpi.has_tlr = false;
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+    static const size_t NUM_SAMPS_PER_BUFF = 10;
+    static const size_t NCHANNELS = 4;
+
+    std::vector<dummy_recv_xport_class> dummy_recv_xports(NCHANNELS, dummy_recv_xport_class(otw_type));
+
+    //generate a bunch of packets
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        ifpi.num_payload_words32 = 10 + i%10;
+        for (size_t ch = 0; ch < NCHANNELS; ch++){
+            dummy_recv_xports[ch].push_back_packet(ifpi);
+        }
+        ifpi.packet_count++;
+        ifpi.tsf += ifpi.num_payload_words32*size_t(TICK_RATE/SAMP_RATE);
+    }
+
+    //create the super receive packet handler
+    uhd::transport::sph::recv_packet_handler handler(NCHANNELS);
+    handler.set_vrt_unpacker(&uhd::transport::vrt::if_hdr_unpack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        handler.set_xport_chan_get_buff(ch, boost::bind(&dummy_recv_xport_class::get_recv_buff, &dummy_recv_xports[ch], _1));
+    }
+    handler.set_converter(otw_type);
+
+    //check the received packets
+    size_t num_accum_samps = 0;
+    std::vector<std::complex<float> > mem(NUM_SAMPS_PER_BUFF*NCHANNELS);
+    std::vector<std::complex<float> *> buffs(NCHANNELS);
+    for (size_t ch = 0; ch < NCHANNELS; ch++){
+        buffs[ch] = &mem[ch*NUM_SAMPS_PER_BUFF];
+    }
+    uhd::rx_metadata_t metadata;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        size_t num_samps_ret = handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+        BOOST_CHECK(metadata.has_time_spec);
+        BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        BOOST_CHECK_EQUAL(num_samps_ret, 10);
+        num_accum_samps += num_samps_ret;
+
+        if (not metadata.more_fragments) continue;
+
+        num_samps_ret = handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_NONE);
+        BOOST_CHECK(not metadata.more_fragments);
+        BOOST_CHECK_EQUAL(metadata.fragment_offset, 10);
+        BOOST_CHECK(metadata.has_time_spec);
+        BOOST_CHECK_TS_CLOSE(metadata.time_spec, uhd::time_spec_t(0, num_accum_samps, SAMP_RATE));
+        BOOST_CHECK_EQUAL(num_samps_ret, i%10);
+        num_accum_samps += num_samps_ret;
+    }
+
+    //subsequent receives should be a timeout
+    for (size_t i = 0; i < 3; i++){
+        std::cout << "timeout check " << i << std::endl;
+        handler.recv(
+            buffs, NUM_SAMPS_PER_BUFF, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::RECV_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(metadata.error_code, uhd::rx_metadata_t::ERROR_CODE_TIMEOUT);
+    }
+
+}
diff --git a/host/tests/sph_send_test.cpp b/host/tests/sph_send_test.cpp
new file mode 100644
index 000000000..ed2f54371
--- /dev/null
+++ b/host/tests/sph_send_test.cpp
@@ -0,0 +1,204 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <boost/test/unit_test.hpp>
+#include "../lib/transport/super_send_packet_handler.hpp"
+#include <boost/shared_array.hpp>
+#include <boost/bind.hpp>
+#include <complex>
+#include <vector>
+#include <list>
+
+#define BOOST_CHECK_TS_CLOSE(a, b) \
+    BOOST_CHECK_CLOSE((a).get_real_secs(), (b).get_real_secs(), 0.001)
+
+/***********************************************************************
+ * A dummy managed send buffer for testing
+ **********************************************************************/
+class dummy_msb : public uhd::transport::managed_send_buffer{
+public:
+    void commit(size_t len){
+        if (len == 0) return;
+        *_len = len;
+    }
+
+    sptr get_new(boost::shared_array<char> mem, size_t *len){
+        _mem = mem;
+        _len = len;
+        return make_managed_buffer(this);
+    }
+
+private:
+    void *get_buff(void) const{return _mem.get();}
+    size_t get_size(void) const{return *_len;}
+
+    boost::shared_array<char> _mem;
+    size_t *_len;
+};
+
+/***********************************************************************
+ * A dummy transport class to fill with fake data
+ **********************************************************************/
+class dummy_send_xport_class{
+public:
+    dummy_send_xport_class(const uhd::otw_type_t &otw_type){
+        _otw_type = otw_type;
+    }
+
+    void pop_front_packet(
+        uhd::transport::vrt::if_packet_info_t &ifpi
+    ){
+        ifpi.num_packet_words32 = _lens.front()/sizeof(boost::uint32_t);
+        if (_otw_type.byteorder == uhd::otw_type_t::BO_BIG_ENDIAN){
+            uhd::transport::vrt::if_hdr_unpack_be(reinterpret_cast<boost::uint32_t *>(_mems.front().get()), ifpi);
+        }
+        if (_otw_type.byteorder == uhd::otw_type_t::BO_LITTLE_ENDIAN){
+            uhd::transport::vrt::if_hdr_unpack_le(reinterpret_cast<boost::uint32_t *>(_mems.front().get()), ifpi);
+        }
+        _mems.pop_front();
+        _lens.pop_front();
+    }
+
+    uhd::transport::managed_send_buffer::sptr get_send_buff(double){
+        _msbs.push_back(dummy_msb());
+        _mems.push_back(boost::shared_array<char>(new char[1000]));
+        _lens.push_back(1000);
+        uhd::transport::managed_send_buffer::sptr mrb = _msbs.back().get_new(_mems.back(), &_lens.back());
+        return mrb;
+    }
+
+private:
+    std::list<boost::shared_array<char> > _mems;
+    std::list<size_t> _lens;
+    std::list<dummy_msb> _msbs; //list means no-realloc
+    uhd::otw_type_t _otw_type;
+};
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_send_one_channel_one_packet_mode){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    dummy_send_xport_class dummy_send_xport(otw_type);
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+
+    //create the super send packet handler
+    uhd::transport::sph::send_packet_handler handler(1);
+    handler.set_vrt_packer(&uhd::transport::vrt::if_hdr_pack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    handler.set_xport_chan_get_buff(0, boost::bind(&dummy_send_xport_class::get_send_buff, &dummy_send_xport, _1));
+    handler.set_converter(otw_type);
+    handler.set_max_samples_per_packet(20);
+
+    //allocate metadata and buffer
+    std::vector<std::complex<float> > buff(20);
+    uhd::tx_metadata_t metadata;
+    metadata.has_time_spec = true;
+    metadata.time_spec = uhd::time_spec_t(0.0);
+
+    //generate the test data
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        metadata.start_of_burst = (i == 0);
+        metadata.end_of_burst = (i == NUM_PKTS_TO_TEST-1);
+        const size_t num_sent = handler.send(
+            &buff.front(), 10 + i%10, metadata,
+            uhd::io_type_t::COMPLEX_FLOAT32,
+            uhd::device::SEND_MODE_ONE_PACKET, 1.0
+        );
+        BOOST_CHECK_EQUAL(num_sent, 10 + i%10);
+        metadata.time_spec += uhd::time_spec_t(0, num_sent, SAMP_RATE);
+    }
+
+    //check the sent packets
+    size_t num_accum_samps = 0;
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        dummy_send_xport.pop_front_packet(ifpi);
+        BOOST_CHECK_EQUAL(ifpi.num_payload_words32, 10+i%10);
+        BOOST_CHECK(ifpi.has_tsi);
+        BOOST_CHECK(ifpi.has_tsf);
+        BOOST_CHECK_EQUAL(ifpi.tsi, 0);
+        BOOST_CHECK_EQUAL(ifpi.tsf, num_accum_samps*TICK_RATE/SAMP_RATE);
+        BOOST_CHECK_EQUAL(ifpi.sob, i == 0);
+        BOOST_CHECK_EQUAL(ifpi.eob, i == NUM_PKTS_TO_TEST-1);
+        num_accum_samps += ifpi.num_payload_words32;
+    }
+}
+
+////////////////////////////////////////////////////////////////////////
+BOOST_AUTO_TEST_CASE(test_sph_send_one_channel_full_buffer_mode){
+////////////////////////////////////////////////////////////////////////
+    uhd::otw_type_t otw_type;
+    otw_type.width = 16;
+    otw_type.shift = 0;
+    otw_type.byteorder = uhd::otw_type_t::BO_BIG_ENDIAN;
+
+    dummy_send_xport_class dummy_send_xport(otw_type);
+
+    static const double TICK_RATE = 100e6;
+    static const double SAMP_RATE = 10e6;
+    static const size_t NUM_PKTS_TO_TEST = 30;
+
+    //create the super send packet handler
+    uhd::transport::sph::send_packet_handler handler(1);
+    handler.set_vrt_packer(&uhd::transport::vrt::if_hdr_pack_be);
+    handler.set_tick_rate(TICK_RATE);
+    handler.set_samp_rate(SAMP_RATE);
+    handler.set_xport_chan_get_buff(0, boost::bind(&dummy_send_xport_class::get_send_buff, &dummy_send_xport, _1));
+    handler.set_converter(otw_type);
+    handler.set_max_samples_per_packet(20);
+
+    //allocate metadata and buffer
+    std::vector<std::complex<float> > buff(20*NUM_PKTS_TO_TEST);
+    uhd::tx_metadata_t metadata;
+    metadata.start_of_burst = true;
+    metadata.end_of_burst = true;
+    metadata.has_time_spec = true;
+    metadata.time_spec = uhd::time_spec_t(0.0);
+
+    //generate the test data
+    const size_t num_sent = handler.send(
+        &buff.front(), buff.size(), metadata,
+        uhd::io_type_t::COMPLEX_FLOAT32,
+        uhd::device::SEND_MODE_FULL_BUFF, 1.0
+    );
+    BOOST_CHECK_EQUAL(num_sent, buff.size());
+
+    //check the sent packets
+    size_t num_accum_samps = 0;
+    uhd::transport::vrt::if_packet_info_t ifpi;
+    for (size_t i = 0; i < NUM_PKTS_TO_TEST; i++){
+        std::cout << "data check " << i << std::endl;
+        dummy_send_xport.pop_front_packet(ifpi);
+        BOOST_CHECK_EQUAL(ifpi.num_payload_words32, 20);
+        BOOST_CHECK(ifpi.has_tsi);
+        BOOST_CHECK(ifpi.has_tsf);
+        BOOST_CHECK_EQUAL(ifpi.tsi, 0);
+        BOOST_CHECK_EQUAL(ifpi.tsf, num_accum_samps*TICK_RATE/SAMP_RATE);
+        BOOST_CHECK_EQUAL(ifpi.sob, i == 0);
+        BOOST_CHECK_EQUAL(ifpi.eob, i == NUM_PKTS_TO_TEST-1);
+        num_accum_samps += ifpi.num_payload_words32;
+    }
+}
diff --git a/host/usrp_e_utils/usrp-e-loopback.c b/host/usrp_e_utils/usrp-e-loopback.c
index 0bd3d3100..762e55ac8 100644
--- a/host/usrp_e_utils/usrp-e-loopback.c
+++ b/host/usrp_e_utils/usrp-e-loopback.c
@@ -51,12 +51,27 @@ static int calc_checksum(struct pkt *p)
 	return sum;
 }
 
+static struct timeval delta_time(struct timeval f, struct timeval s)
+{
+	struct timeval d;
+
+	if (f.tv_usec > s.tv_usec) {
+		d.tv_usec = f.tv_usec - s.tv_usec;
+		d.tv_sec = f.tv_sec - s.tv_sec;
+	} else {
+		d.tv_usec = f.tv_usec - s.tv_usec + 1e6;
+		d.tv_sec = f.tv_sec - s.tv_sec - 1;
+	}
+
+	return d;
+}
+
 static void *read_thread(void *threadid)
 {
 	int cnt, prev_seq_num, pkt_count, seq_num_failure;
 	struct pkt *p;
-	unsigned long bytes_transfered, elapsed_seconds;
-	struct timeval start_time, finish_time;
+	unsigned long bytes_transfered;
+	struct timeval start_time;
 	int rb_read;
 
 	printf("Greetings from the reading thread!\n");
@@ -125,11 +140,15 @@ static void *read_thread(void *threadid)
 		bytes_transfered += cnt;
 
 		if (bytes_transfered > (100 * 1000000)) {
+			struct timeval finish_time, d_time;
+			float elapsed_seconds;
+
 			gettimeofday(&finish_time, NULL);
-			elapsed_seconds = finish_time.tv_sec - start_time.tv_sec;
+			d_time = delta_time(finish_time, start_time);
+			elapsed_seconds = (float)d_time.tv_sec + ((float)d_time.tv_usec * 1e-6f);
 
 			printf("RX data transfer rate = %f K Samples/second\n",
-				(float) bytes_transfered / (float) elapsed_seconds / 4000);
+				(float) bytes_transfered / elapsed_seconds / 4000.0f);
 
 
 			start_time = finish_time;
diff --git a/host/usrp_e_utils/usrp-e-timed.c b/host/usrp_e_utils/usrp-e-timed.c
index 06dfdf512..407564429 100644
--- a/host/usrp_e_utils/usrp-e-timed.c
+++ b/host/usrp_e_utils/usrp-e-timed.c
@@ -273,7 +273,7 @@ static void *write_thread(void *threadid)
 
 			d_time = delta_time(finish_time, start_time);
 
-			elapsed_seconds = (float)d_time.tv_sec - ((float)d_time.tv_usec * 1e-6f);
+			elapsed_seconds = (float)d_time.tv_sec + ((float)d_time.tv_usec * 1e-6f);
 
 			printf("Bytes transfered = %ld, elapsed seconds = %f\n", bytes_transfered, elapsed_seconds);
 			printf("TX data transfer rate = %f K Samples/second\n",