sbx: squashed Ben's SBX work

5 files changed, 742 insertions, 403 deletions

diff --git a/host/lib/usrp/dboard/CMakeLists.txt b/host/lib/usrp/dboard/CMakeLists.txt
index cb71e695b..a865a7858 100644
--- a/host/lib/usrp/dboard/CMakeLists.txt
+++ b/host/lib/usrp/dboard/CMakeLists.txt
@@ -23,7 +23,9 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/db_basic_and_lf.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/db_rfx.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/db_xcvr2450.cpp
-    #${CMAKE_CURRENT_SOURCE_DIR}/db_sbx.cpp
+    #${CMAKE_CURRENT_SOURCE_DIR}/db_sbx_common.cpp
+    #${CMAKE_CURRENT_SOURCE_DIR}/db_sbx_version3.cpp
+    #${CMAKE_CURRENT_SOURCE_DIR}/db_sbx_version4.cpp
     #${CMAKE_CURRENT_SOURCE_DIR}/db_wbx_common.cpp
     #${CMAKE_CURRENT_SOURCE_DIR}/db_wbx_simple.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/db_dbsrx.cpp
diff --git a/host/lib/usrp/dboard/db_sbx.cpp b/host/lib/usrp/dboard/db_sbx_common.cpp
index 40dbd286d..51a0f0100 100644
--- a/host/lib/usrp/dboard/db_sbx.cpp
+++ b/host/lib/usrp/dboard/db_sbx_common.cpp
@@ -15,228 +15,13 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 //
 
-// Common IO Pins
-#define LO_LPF_EN       (1 << 15)
-#define ADF4350_CE      (1 << 3)
-#define ADF4350_PDBRF   (1 << 2)
-#define ADF4350_MUXOUT  (1 << 1)                // INPUT!!!
-#define LOCKDET_MASK    (1 << 0)                // INPUT!!!
-
-// TX IO Pins
-#define TRSW            (1 << 14)               // 0 = TX, 1 = RX 
-#define TX_LED_TXRX     (1 << 7)                // LED for TX Antenna Selection TX/RX
-#define TX_LED_LD       (1 << 6)                // LED for TX Lock Detect
-#define DIS_POWER_TX    (1 << 5)                // on UNIT_TX, 0 powers up TX
-#define TX_ENABLE       (1 << 4)                // on UNIT_TX, 0 disables TX Mixer
-
-// RX IO Pins
-#define LNASW           (1 << 14)               // 0 = TX/RX, 1 = RX2
-#define RX_LED_RX1RX2   (1 << 7)                // LED for RX Antenna Selection RX1/RX2
-#define RX_LED_LD       (1 << 6)                // LED for RX Lock Detect
-#define DIS_POWER_RX    (1 << 5)                // on UNIT_RX, 0 powers up RX
-#define RX_DISABLE      (1 << 4)                // on UNIT_RX, 1 disables RX Mixer and Baseband
-
-// RX Attenuator Pins
-#define RX_ATTN_SHIFT   8                       // lsb of RX Attenuator Control
-#define RX_ATTN_MASK    (63 << RX_ATTN_SHIFT)   // valid bits of RX Attenuator Control
-
-// TX Attenuator Pins
-#define TX_ATTN_SHIFT   8                       // lsb of RX Attenuator Control
-#define TX_ATTN_MASK    (63 << TX_ATTN_SHIFT)   // valid bits of RX Attenuator Control
-
-// Mixer functions
-#define TX_MIXER_ENB    (ADF4350_PDBRF)
-#define TX_MIXER_DIS    0
-
-#define RX_MIXER_ENB    (ADF4350_PDBRF)
-#define RX_MIXER_DIS    0
-
-// Pin functions
-#define TX_LED_IO       (TX_LED_TXRX|TX_LED_LD)     // LED gpio lines, pull down for LED
-#define TXIO_MASK       (LO_LPF_EN|TRSW|ADF4350_CE|ADF4350_PDBRF|TX_ATTN_MASK|DIS_POWER_TX|TX_ENABLE)
-
-#define RX_LED_IO       (RX_LED_RX1RX2|RX_LED_LD)   // LED gpio lines, pull down for LED
-#define RXIO_MASK       (LO_LPF_EN|LNASW|ADF4350_CE|ADF4350_PDBRF|RX_ATTN_MASK|DIS_POWER_RX|RX_DISABLE)
-
-// Power functions
-#define TX_POWER_UP     (ADF4350_CE|TX_ENABLE)
-#define TX_POWER_DOWN   (DIS_POWER_TX)
-
-#define RX_POWER_UP     (ADF4350_CE)
-#define RX_POWER_DOWN   (DIS_POWER_RX)
-
-// Antenna constants
-#define ANT_TX          TRSW                    //the tx line is transmitting
-#define ANT_RX          0                       //the tx line is receiving
-#define ANT_TXRX        0                       //the rx line is on txrx
-#define ANT_RX2         LNASW                   //the rx line in on rx2
-#define ANT_XX          LNASW                   //dont care how the antenna is set
-
+#include "db_sbx_common.hpp"
 #include "adf4350_regs.hpp"
-#include <uhd/types/dict.hpp>
-#include <uhd/types/ranges.hpp>
-#include <uhd/types/sensors.hpp>
-#include <uhd/utils/assert_has.hpp>
-#include <uhd/utils/log.hpp>
-#include <uhd/utils/static.hpp>
-#include <uhd/utils/algorithm.hpp>
-#include <uhd/utils/msg.hpp>
-#include <uhd/usrp/dboard_base.hpp>
-#include <uhd/usrp/dboard_manager.hpp>
-#include <boost/assign/list_of.hpp>
-#include <boost/format.hpp>
-#include <boost/math/special_functions/round.hpp>
-#include <boost/thread.hpp>
 
 using namespace uhd;
 using namespace uhd::usrp;
 using namespace boost::assign;
 
-/***********************************************************************
- * The SBX dboard constants
- **********************************************************************/
-static const freq_range_t sbx_freq_range(400e6, 4.4e9);
-
-static const freq_range_t sbx_tx_lo_2dbm = list_of
-    (range_t(0.35e9, 0.37e9))
-;
-
-static const freq_range_t sbx_enable_tx_lo_filter = list_of
-    (range_t(0.4e9, 1.5e9))
-;
-
-static const freq_range_t sbx_enable_rx_lo_filter = list_of
-    (range_t(0.4e9, 1.5e9))
-;
-
-static const prop_names_t sbx_tx_antennas = list_of("TX/RX");
-
-static const prop_names_t sbx_rx_antennas = list_of("TX/RX")("RX2");
-
-static const uhd::dict<std::string, gain_range_t> sbx_tx_gain_ranges = map_list_of
-    ("PGA0", gain_range_t(0, 31.5, double(0.5)))
-;
-
-static const uhd::dict<std::string, gain_range_t> sbx_rx_gain_ranges = map_list_of
-    ("PGA0", gain_range_t(0, 31.5, double(0.5)))
-;
-
-/***********************************************************************
- * The SBX dboard
- **********************************************************************/
-class sbx_xcvr : public xcvr_dboard_base{
-public:
-    sbx_xcvr(ctor_args_t args);
-    ~sbx_xcvr(void);
-
-    void rx_get(const wax::obj &key, wax::obj &val);
-    void rx_set(const wax::obj &key, const wax::obj &val);
-
-    void tx_get(const wax::obj &key, wax::obj &val);
-    void tx_set(const wax::obj &key, const wax::obj &val);
-
-private:
-    uhd::dict<std::string, double> _tx_gains, _rx_gains;
-    double       _rx_lo_freq, _tx_lo_freq;
-    std::string  _tx_ant, _rx_ant;
-
-    void set_rx_lo_freq(double freq);
-    void set_tx_lo_freq(double freq);
-    void set_rx_ant(const std::string &ant);
-    void set_tx_ant(const std::string &ant);
-    void set_rx_gain(double gain, const std::string &name);
-    void set_tx_gain(double gain, const std::string &name);
-
-    void update_atr(void);
-
-    /*!
-     * Set the LO frequency for the particular dboard unit.
-     * \param unit which unit rx or tx
-     * \param target_freq the desired frequency in Hz
-     * \return the actual frequency in Hz
-     */
-    double set_lo_freq(dboard_iface::unit_t unit, double target_freq);
-
-    /*!
-     * Get the lock detect status of the LO.
-     * \param unit which unit rx or tx
-     * \return true for locked
-     */
-    bool get_locked(dboard_iface::unit_t unit){
-        return (this->get_iface()->read_gpio(unit) & LOCKDET_MASK) != 0;
-    }
-
-    /*!
-     * Flash the LEDs
-     */
-    void flash_leds(void) {
-        //Remove LED gpios from ATR control temporarily and set to outputs
-        this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_TX, TXIO_MASK);
-        this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, RXIO_MASK);
-        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_TX, (TXIO_MASK|RX_LED_IO));
-        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
-
-        /*
-        //flash All LEDs
-        for (int i = 0; i < 3; i++) {
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_IO, RX_LED_IO);
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_IO, TX_LED_IO);
-
-            boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0, RX_LED_IO);
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, 0, TX_LED_IO);
-
-            boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-        }
-        */
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_LD, TX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_TXRX|TX_LED_LD, TX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_LD, RX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_RX1RX2|RX_LED_LD, RX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_LD, RX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0, RX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_LD, TX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, 0, TX_LED_IO);
-        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-        /*
-        //flash All LEDs
-        for (int i = 0; i < 3; i++) {
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0, RX_LED_IO);
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, 0, TX_LED_IO);
-
-            boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_IO, RX_LED_IO);
-            this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_IO, TX_LED_IO);
-
-            boost::this_thread::sleep(boost::posix_time::milliseconds(100));
-        }
-        */
-        //Put LED gpios back in ATR control and update atr
-        this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
-        this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
-        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
-        this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
-    }
-
-};
 
 /***********************************************************************
  * Register the SBX dboard (min freq, max freq, rx div2, tx div2)
@@ -247,46 +32,9 @@ static dboard_base::sptr make_sbx(dboard_base::ctor_args_t args){
 
 UHD_STATIC_BLOCK(reg_sbx_dboards){
     dboard_manager::register_dboard(0x0054, 0x0055, &make_sbx, "SBX");
+    dboard_manager::register_dboard(0x0065, 0x0064, &make_sbx, "SBX v4");
 }
 
-/***********************************************************************
- * Structors
- **********************************************************************/
-sbx_xcvr::sbx_xcvr(ctor_args_t args) : xcvr_dboard_base(args){
-
-    //enable the clocks that we need
-    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_TX, true);
-    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_RX, true);
-
-    //set the gpio directions and atr controls (identically)
-    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
-    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
-    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
-    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
-
-    //flash LEDs
-    flash_leds();
-
-    UHD_LOGV(often) << boost::format(
-        "SBX GPIO Direction: RX: 0x%08x, TX: 0x%08x"
-    ) % RXIO_MASK % TXIO_MASK << std::endl;
-
-    //set some default values
-    set_rx_lo_freq((sbx_freq_range.start() + sbx_freq_range.stop())/2.0);
-    set_tx_lo_freq((sbx_freq_range.start() + sbx_freq_range.stop())/2.0);
-    set_rx_ant("RX2");
-
-    BOOST_FOREACH(const std::string &name, sbx_tx_gain_ranges.keys()){
-        set_tx_gain(sbx_tx_gain_ranges[name].start(), name);
-    }
-    BOOST_FOREACH(const std::string &name, sbx_rx_gain_ranges.keys()){
-        set_rx_gain(sbx_rx_gain_ranges[name].start(), name);
-    }
-}
-
-sbx_xcvr::~sbx_xcvr(void){
-    /* NOP */
-}
 
 /***********************************************************************
  * Gain Handling
@@ -302,7 +50,6 @@ static int rx_pga0_gain_to_iobits(double &gain){
     int attn_code = int(floor(attn*2));
     int iobits = ((~attn_code) << RX_ATTN_SHIFT) & RX_ATTN_MASK;
 
-    
     UHD_LOGV(often) << boost::format(
         "SBX TX Attenuation: %f dB, Code: %d, IO Bits %x, Mask: %x"
     ) % attn % attn_code % (iobits & RX_ATTN_MASK) % RX_ATTN_MASK << std::endl;
@@ -324,7 +71,6 @@ static int tx_pga0_gain_to_iobits(double &gain){
     int attn_code = int(floor(attn*2));
     int iobits = ((~attn_code) << TX_ATTN_SHIFT) & TX_ATTN_MASK;
 
-    
     UHD_LOGV(often) << boost::format(
         "SBX TX Attenuation: %f dB, Code: %d, IO Bits %x, Mask: %x"
     ) % attn % attn_code % (iobits & TX_ATTN_MASK) % TX_ATTN_MASK << std::endl;
@@ -359,6 +105,57 @@ void sbx_xcvr::set_rx_gain(double gain, const std::string &name){
     else UHD_THROW_INVALID_CODE_PATH();
 }
 
+
+/***********************************************************************
+ * Structors
+ **********************************************************************/
+sbx_xcvr::sbx_xcvr(ctor_args_t args) : xcvr_dboard_base(args){
+    switch(get_rx_id().to_uint16()) {
+        case 0x054:
+            db_actual = sbx_versionx_sptr(new sbx_version3(this));
+            break;
+        case 0x065:
+            db_actual = sbx_versionx_sptr(new sbx_version4(this));
+            break;
+        default:
+            /* We didn't recognize the version of the board... */
+            UHD_THROW_INVALID_CODE_PATH();
+    }
+
+    //enable the clocks that we need
+    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_TX, true);
+    this->get_iface()->set_clock_enabled(dboard_iface::UNIT_RX, true);
+
+    //set the gpio directions and atr controls (identically)
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
+    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
+    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
+
+    //flash LEDs
+    flash_leds();
+
+    UHD_LOGV(often) << boost::format(
+        "SBX GPIO Direction: RX: 0x%08x, TX: 0x%08x"
+    ) % RXIO_MASK % TXIO_MASK << std::endl;
+
+    //set some default values
+    set_rx_lo_freq((sbx_freq_range.start() + sbx_freq_range.stop())/2.0);
+    set_tx_lo_freq((sbx_freq_range.start() + sbx_freq_range.stop())/2.0);
+    set_rx_ant("RX2");
+
+    BOOST_FOREACH(const std::string &name, sbx_tx_gain_ranges.keys()){
+        set_tx_gain(sbx_tx_gain_ranges[name].start(), name);
+    }
+    BOOST_FOREACH(const std::string &name, sbx_rx_gain_ranges.keys()){
+        set_rx_gain(sbx_rx_gain_ranges[name].start(), name);
+    }
+}
+
+sbx_xcvr::~sbx_xcvr(void){
+    /* NOP */
+}
+
 /***********************************************************************
  * Antenna Handling
  **********************************************************************/
@@ -422,158 +219,16 @@ void sbx_xcvr::set_tx_ant(const std::string &ant){
  * Tuning
  **********************************************************************/
 void sbx_xcvr::set_rx_lo_freq(double freq){
-    _rx_lo_freq = set_lo_freq(dboard_iface::UNIT_RX, freq);
+    _rx_lo_freq = db_actual->set_lo_freq(dboard_iface::UNIT_RX, freq);
 }
 
 void sbx_xcvr::set_tx_lo_freq(double freq){
-    _tx_lo_freq = set_lo_freq(dboard_iface::UNIT_TX, freq);
+    _tx_lo_freq = db_actual->set_lo_freq(dboard_iface::UNIT_TX, freq);
 }
 
-double sbx_xcvr::set_lo_freq(
-    dboard_iface::unit_t unit,
-    double target_freq
-){
-    UHD_LOGV(often) << boost::format(
-        "SBX tune: target frequency %f Mhz"
-    ) % (target_freq/1e6) << std::endl;
-
-    //clip the input
-    target_freq = sbx_freq_range.clip(target_freq);
-
-    //map prescaler setting to mininmum integer divider (N) values (pg.18 prescaler)
-    static const uhd::dict<int, int> prescaler_to_min_int_div = map_list_of
-        (0,23) //adf4350_regs_t::PRESCALER_4_5
-        (1,75) //adf4350_regs_t::PRESCALER_8_9
-    ;
-
-    //map rf divider select output dividers to enums
-    static const uhd::dict<int, adf4350_regs_t::rf_divider_select_t> rfdivsel_to_enum = map_list_of
-        (1,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV1)
-        (2,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV2)
-        (4,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV4)
-        (8,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV8)
-        (16, adf4350_regs_t::RF_DIVIDER_SELECT_DIV16)
-    ;
-
-    double actual_freq, pfd_freq;
-    double ref_freq = this->get_iface()->get_clock_rate(unit);
-    int R=0, BS=0, N=0, FRAC=0, MOD=0;
-    int RFdiv = 1;
-    adf4350_regs_t::reference_divide_by_2_t T     = adf4350_regs_t::REFERENCE_DIVIDE_BY_2_DISABLED;
-    adf4350_regs_t::reference_doubler_t     D     = adf4350_regs_t::REFERENCE_DOUBLER_DISABLED;    
-
-    //Reference doubler for 50% duty cycle
-    // if ref_freq < 12.5MHz enable regs.reference_divide_by_2
-    if(ref_freq <= 12.5e6) D = adf4350_regs_t::REFERENCE_DOUBLER_ENABLED;
-
-    //increase RF divider until acceptable VCO frequency
-    //start with target_freq*2 because mixer has divide by 2
-    double vco_freq = target_freq;
-    while (vco_freq < 2.2e9) {
-        vco_freq *= 2;
-        RFdiv *= 2;
-    }
-
-    //use 8/9 prescaler for vco_freq > 3 GHz (pg.18 prescaler)
-    adf4350_regs_t::prescaler_t prescaler = vco_freq > 3e9 ? adf4350_regs_t::PRESCALER_8_9 : adf4350_regs_t::PRESCALER_4_5;
 
-    /*
-     * The goal here is to loop though possible R dividers,
-     * band select clock dividers, N (int) dividers, and FRAC 
-     * (frac) dividers.
-     *
-     * Calculate the N and F dividers for each set of values.
-     * The loop exists when it meets all of the constraints.
-     * The resulting loop values are loaded into the registers.
-     *
-     * from pg.21
-     *
-     * f_pfd = f_ref*(1+D)/(R*(1+T))
-     * f_vco = (N + (FRAC/MOD))*f_pfd
-     *    N = f_vco/f_pfd - FRAC/MOD = f_vco*((R*(T+1))/(f_ref*(1+D))) - FRAC/MOD
-     * f_rf = f_vco/RFdiv)
-     * f_actual = f_rf/2
-     */
-    for(R = 1; R <= 1023; R+=1){
-        //PFD input frequency = f_ref/R ... ignoring Reference doubler/divide-by-2 (D & T)
-        pfd_freq = ref_freq*(1+D)/(R*(1+T));
-
-        //keep the PFD frequency at or below 25MHz (Loop Filter Bandwidth)
-        if (pfd_freq > 25e6) continue;
-
-        //ignore fractional part of tuning
-        N = int(std::floor(vco_freq/pfd_freq));
-
-        //keep N > minimum int divider requirement
-        if (N < prescaler_to_min_int_div[prescaler]) continue;
-
-        for(BS=1; BS <= 255; BS+=1){
-            //keep the band select frequency at or below 100KHz
-            //constraint on band select clock
-            if (pfd_freq/BS > 100e3) continue;
-            goto done_loop;
-        }
-    } done_loop:
-
-    //Fractional-N calculation
-    MOD = 4095; //max fractional accuracy
-    FRAC = int((vco_freq/pfd_freq - N)*MOD);
-
-    //Reference divide-by-2 for 50% duty cycle
-    // if R even, move one divide by 2 to to regs.reference_divide_by_2
-    if(R % 2 == 0){
-        T = adf4350_regs_t::REFERENCE_DIVIDE_BY_2_ENABLED;
-        R /= 2;
-    }
-
-    //actual frequency calculation
-    actual_freq = double((N + (double(FRAC)/double(MOD)))*ref_freq*(1+int(D))/(R*(1+int(T)))/RFdiv);
-
-    UHD_LOGV(often)
-        << boost::format("SBX Intermediates: ref=%0.2f, outdiv=%f, fbdiv=%f") % (ref_freq*(1+int(D))/(R*(1+int(T)))) % double(RFdiv*2) % double(N + double(FRAC)/double(MOD)) << std::endl
-        << boost::format("SBX tune: R=%d, BS=%d, N=%d, FRAC=%d, MOD=%d, T=%d, D=%d, RFdiv=%d, LD=%d"
-            ) % R % BS % N % FRAC % MOD % T % D % RFdiv % get_locked(unit)<< std::endl
-        << boost::format("SBX Frequencies (MHz): REQ=%0.2f, ACT=%0.2f, VCO=%0.2f, PFD=%0.2f, BAND=%0.2f"
-            ) % (target_freq/1e6) % (actual_freq/1e6) % (vco_freq/1e6) % (pfd_freq/1e6) % (pfd_freq/BS/1e6) << std::endl;
-
-    //load the register values
-    adf4350_regs_t regs;
-
-    if ((unit == dboard_iface::UNIT_TX) and (actual_freq == sbx_tx_lo_2dbm.clip(actual_freq))) 
-        regs.output_power = adf4350_regs_t::OUTPUT_POWER_2DBM;
-    else
-        regs.output_power = adf4350_regs_t::OUTPUT_POWER_5DBM;
-
-    regs.frac_12_bit = FRAC;
-    regs.int_16_bit = N;
-    regs.mod_12_bit = MOD;
-    regs.prescaler = prescaler;
-    regs.r_counter_10_bit = R;
-    regs.reference_divide_by_2 = T;
-    regs.reference_doubler = D;
-    regs.band_select_clock_div = BS;
-    UHD_ASSERT_THROW(rfdivsel_to_enum.has_key(RFdiv));
-    regs.rf_divider_select = rfdivsel_to_enum[RFdiv];
-
-    //write the registers
-    //correct power-up sequence to write registers (5, 4, 3, 2, 1, 0)
-    int addr;
-
-    for(addr=5; addr>=0; addr--){
-        UHD_LOGV(often) << boost::format(
-            "SBX SPI Reg (0x%02x): 0x%08x"
-        ) % addr % regs.get_reg(addr) << std::endl;
-        this->get_iface()->write_spi(
-            unit, spi_config_t::EDGE_RISE,
-            regs.get_reg(addr), 32
-        );
-    }
-
-    //return the actual frequency
-    UHD_LOGV(often) << boost::format(
-        "SBX tune: actual frequency %f Mhz"
-    ) % (actual_freq/1e6) << std::endl;
-    return actual_freq;
+double sbx_xcvr::set_lo_freq(dboard_iface::unit_t unit, double target_freq) {
+    return db_actual->set_lo_freq(unit, target_freq);
 }
 
 /***********************************************************************
@@ -783,3 +438,77 @@ void sbx_xcvr::tx_set(const wax::obj &key_, const wax::obj &val){
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
+
+
+bool sbx_xcvr::get_locked(dboard_iface::unit_t unit) {
+    return (this->get_iface()->read_gpio(unit) & LOCKDET_MASK) != 0;
+}
+
+
+void sbx_xcvr::flash_leds(void) {
+    //Remove LED gpios from ATR control temporarily and set to outputs
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_TX, TXIO_MASK);
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, RXIO_MASK);
+    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_TX, (TXIO_MASK|RX_LED_IO));
+    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
+
+    /*
+    //flash All LEDs
+    for (int i = 0; i < 3; i++) {
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_IO, RX_LED_IO);
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_IO, TX_LED_IO);
+
+        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0, RX_LED_IO);
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, 0, TX_LED_IO);
+
+        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+    }
+    */
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_LD, TX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_TXRX|TX_LED_LD, TX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_LD, RX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_RX1RX2|RX_LED_LD, RX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_LD, RX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0, RX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_LD, TX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, 0, TX_LED_IO);
+    boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+    /*
+    //flash All LEDs
+    for (int i = 0; i < 3; i++) {
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, 0, RX_LED_IO);
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, 0, TX_LED_IO);
+
+        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_RX, RX_LED_IO, RX_LED_IO);
+        this->get_iface()->set_gpio_out(dboard_iface::UNIT_TX, TX_LED_IO, TX_LED_IO);
+
+        boost::this_thread::sleep(boost::posix_time::milliseconds(100));
+    }
+    */
+    //Put LED gpios back in ATR control and update atr
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
+    this->get_iface()->set_pin_ctrl(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
+    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_TX, (TXIO_MASK|TX_LED_IO));
+    this->get_iface()->set_gpio_ddr(dboard_iface::UNIT_RX, (RXIO_MASK|RX_LED_IO));
+}
+
diff --git a/host/lib/usrp/dboard/db_sbx_common.hpp b/host/lib/usrp/dboard/db_sbx_common.hpp
new file mode 100644
index 000000000..5ff84811a
--- /dev/null
+++ b/host/lib/usrp/dboard/db_sbx_common.hpp
@@ -0,0 +1,233 @@
+//
+// 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/>.
+//
+
+
+
+// Common IO Pins
+#define LO_LPF_EN       (1 << 15)
+#define SYNTH_CE        (1 << 3)
+#define SYNTH_PDBRF     (1 << 2)
+#define SYNTH_MUXOUT    (1 << 1)                // INPUT!!!
+#define LOCKDET_MASK    (1 << 0)                // INPUT!!!
+
+// TX IO Pins
+#define TRSW            (1 << 14)               // 0 = TX, 1 = RX 
+#define TX_LED_TXRX     (1 << 7)                // LED for TX Antenna Selection TX/RX
+#define TX_LED_LD       (1 << 6)                // LED for TX Lock Detect
+#define DIS_POWER_TX    (1 << 5)                // on UNIT_TX, 0 powers up TX
+#define TX_ENABLE       (1 << 4)                // on UNIT_TX, 0 disables TX Mixer
+
+// RX IO Pins
+#define LNASW           (1 << 14)               // 0 = TX/RX, 1 = RX2
+#define RX_LED_RX1RX2   (1 << 7)                // LED for RX Antenna Selection RX1/RX2
+#define RX_LED_LD       (1 << 6)                // LED for RX Lock Detect
+#define DIS_POWER_RX    (1 << 5)                // on UNIT_RX, 0 powers up RX
+#define RX_DISABLE      (1 << 4)                // on UNIT_RX, 1 disables RX Mixer and Baseband
+
+// RX Attenuator Pins
+#define RX_ATTN_SHIFT   8                       // lsb of RX Attenuator Control
+#define RX_ATTN_MASK    (63 << RX_ATTN_SHIFT)   // valid bits of RX Attenuator Control
+
+// TX Attenuator Pins
+#define TX_ATTN_SHIFT   8                       // lsb of RX Attenuator Control
+#define TX_ATTN_MASK    (63 << TX_ATTN_SHIFT)   // valid bits of RX Attenuator Control
+
+// Mixer functions
+#define TX_MIXER_ENB    (SYNTH_PDBRF)
+#define TX_MIXER_DIS    0
+
+#define RX_MIXER_ENB    (SYNTH_PDBRF)
+#define RX_MIXER_DIS    0
+
+// Pin functions
+#define TX_LED_IO       (TX_LED_TXRX|TX_LED_LD)     // LED gpio lines, pull down for LED
+#define TXIO_MASK       (LO_LPF_EN|TRSW|SYNTH_CE|SYNTH_PDBRF|TX_ATTN_MASK|DIS_POWER_TX|TX_ENABLE)
+
+#define RX_LED_IO       (RX_LED_RX1RX2|RX_LED_LD)   // LED gpio lines, pull down for LED
+#define RXIO_MASK       (LO_LPF_EN|LNASW|SYNTH_CE|SYNTH_PDBRF|RX_ATTN_MASK|DIS_POWER_RX|RX_DISABLE)
+
+// Power functions
+#define TX_POWER_UP     (SYNTH_CE|TX_ENABLE)
+#define TX_POWER_DOWN   (DIS_POWER_TX)
+
+#define RX_POWER_UP     (SYNTH_CE)
+#define RX_POWER_DOWN   (DIS_POWER_RX)
+
+// Antenna constants
+#define ANT_TX          TRSW                    //the tx line is transmitting
+#define ANT_RX          0                       //the tx line is receiving
+#define ANT_TXRX        0                       //the rx line is on txrx
+#define ANT_RX2         LNASW                   //the rx line in on rx2
+#define ANT_XX          LNASW                   //dont care how the antenna is set
+
+
+#include <uhd/types/dict.hpp>
+#include <uhd/types/ranges.hpp>
+#include <uhd/types/sensors.hpp>
+#include <uhd/utils/assert_has.hpp>
+#include <uhd/utils/log.hpp>
+#include <uhd/utils/static.hpp>
+#include <uhd/utils/algorithm.hpp>
+#include <uhd/utils/msg.hpp>
+#include <uhd/usrp/dboard_base.hpp>
+#include <uhd/usrp/dboard_manager.hpp>
+#include <boost/assign/list_of.hpp>
+#include <boost/format.hpp>
+#include <boost/math/special_functions/round.hpp>
+#include <boost/thread.hpp>
+
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace boost::assign;
+
+
+/***********************************************************************
+ * The SBX dboard constants
+ **********************************************************************/
+static const freq_range_t sbx_freq_range(400e6, 4.4e9);
+
+static const freq_range_t sbx_tx_lo_2dbm = list_of
+    (range_t(0.35e9, 0.37e9))
+;
+
+static const freq_range_t sbx_enable_tx_lo_filter = list_of
+    (range_t(0.4e9, 1.5e9))
+;
+
+static const freq_range_t sbx_enable_rx_lo_filter = list_of
+    (range_t(0.4e9, 1.5e9))
+;
+
+static const prop_names_t sbx_tx_antennas = list_of("TX/RX");
+
+static const prop_names_t sbx_rx_antennas = list_of("TX/RX")("RX2");
+
+static const uhd::dict<std::string, gain_range_t> sbx_tx_gain_ranges = map_list_of
+    ("PGA0", gain_range_t(0, 31.5, double(0.5)))
+;
+
+static const uhd::dict<std::string, gain_range_t> sbx_rx_gain_ranges = map_list_of
+    ("PGA0", gain_range_t(0, 31.5, double(0.5)))
+;
+
+/***********************************************************************
+ * The SBX dboard
+ **********************************************************************/
+class sbx_xcvr : public xcvr_dboard_base{
+public:
+    sbx_xcvr(ctor_args_t args);
+    ~sbx_xcvr(void);
+
+    void rx_get(const wax::obj &key, wax::obj &val);
+    void rx_set(const wax::obj &key, const wax::obj &val);
+
+    void tx_get(const wax::obj &key, wax::obj &val);
+    void tx_set(const wax::obj &key, const wax::obj &val);
+
+protected:
+
+    uhd::dict<std::string, double> _tx_gains, _rx_gains;
+    double       _rx_lo_freq, _tx_lo_freq;
+    std::string  _tx_ant, _rx_ant;
+
+    void set_rx_lo_freq(double freq);
+    void set_tx_lo_freq(double freq);
+    void set_rx_ant(const std::string &ant);
+    void set_tx_ant(const std::string &ant);
+    void set_rx_gain(double gain, const std::string &name);
+    void set_tx_gain(double gain, const std::string &name);
+
+    void update_atr(void);
+
+    /*!
+     * Set the LO frequency for the particular dboard unit.
+     * \param unit which unit rx or tx
+     * \param target_freq the desired frequency in Hz
+     * \return the actual frequency in Hz
+     */
+    virtual double set_lo_freq(dboard_iface::unit_t unit, double target_freq);
+
+    /*!
+     * Get the lock detect status of the LO.
+     * \param unit which unit rx or tx
+     * \return true for locked
+     */
+    bool get_locked(dboard_iface::unit_t unit);
+
+    /*!
+     * Flash the LEDs
+     */
+    void flash_leds(void);
+
+    /*!
+     * Version-agnostic ABC that wraps version-specific implementations of the
+     * WBX base daughterboard.
+     *
+     * This class is an abstract base class, and thus is impossible to
+     * instantiate.
+     */
+    class sbx_versionx {
+    public:
+        sbx_versionx() {}
+        ~sbx_versionx(void) {}
+
+        virtual double set_lo_freq(dboard_iface::unit_t unit, double target_freq) = 0;
+    };
+
+    /*!
+     * Version 3 of the SBX Daughterboard
+     */
+    class sbx_version3 : public sbx_versionx {
+    public:
+        sbx_version3(sbx_xcvr *_self_sbx_xcvr);
+        ~sbx_version3(void);
+
+        double set_lo_freq(dboard_iface::unit_t unit, double target_freq);
+
+        /*! This is the registered instance of the wrapper class, sbx_base. */
+        sbx_xcvr *self_base;
+    };
+
+    /*!
+     * Version 4 of the SBX Daughterboard
+     *
+     * The only difference in the fourth revision is the ADF4351 vs the ADF4350.
+     */
+    class sbx_version4 : public sbx_versionx {
+    public:
+        sbx_version4(sbx_xcvr *_self_sbx_xcvr);
+        ~sbx_version4(void);
+
+        double set_lo_freq(dboard_iface::unit_t unit, double target_freq);
+
+        /*! This is the registered instance of the wrapper class, sbx_base. */
+        sbx_xcvr *self_base;
+    };
+
+    /*!
+     * Handle to the version-specific implementation of the SBX.
+     *
+     * Since many of this class's functions are dependent on the version of the
+     * SBX board, this class will instantiate an object of the appropriate
+     * sbx_version* subclass, and invoke any relevant functions through that
+     * object.  This pointer is set to the proper object at construction time.
+     */
+    typedef boost::shared_ptr<sbx_versionx> sbx_versionx_sptr;
+    sbx_versionx_sptr db_actual;
+};
+
diff --git a/host/lib/usrp/dboard/db_sbx_version3.cpp b/host/lib/usrp/dboard/db_sbx_version3.cpp
new file mode 100644
index 000000000..b5aad8aa5
--- /dev/null
+++ b/host/lib/usrp/dboard/db_sbx_version3.cpp
@@ -0,0 +1,186 @@
+//
+// 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 "adf4350_regs.hpp"
+#include "db_sbx_common.hpp"
+
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace boost::assign;
+
+/***********************************************************************
+ * Structors
+ **********************************************************************/
+sbx_xcvr::sbx_version3::sbx_version3(sbx_xcvr *_self_sbx_xcvr) {
+    //register the handle to our base SBX class
+    self_base = _self_sbx_xcvr;
+}
+
+sbx_xcvr::sbx_version3::~sbx_version3(void){
+    /* NOP */
+}
+
+
+/***********************************************************************
+ * Tuning
+ **********************************************************************/
+double sbx_xcvr::sbx_version3::set_lo_freq(dboard_iface::unit_t unit, double target_freq) {
+    UHD_LOGV(often) << boost::format(
+        "SBX tune: target frequency %f Mhz"
+    ) % (target_freq/1e6) << std::endl;
+
+    //clip the input
+    target_freq = sbx_freq_range.clip(target_freq);
+
+    //map prescaler setting to mininmum integer divider (N) values (pg.18 prescaler)
+    static const uhd::dict<int, int> prescaler_to_min_int_div = map_list_of
+        (0,23) //adf4350_regs_t::PRESCALER_4_5
+        (1,75) //adf4350_regs_t::PRESCALER_8_9
+    ;
+
+    //map rf divider select output dividers to enums
+    static const uhd::dict<int, adf4350_regs_t::rf_divider_select_t> rfdivsel_to_enum = map_list_of
+        (1,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV1)
+        (2,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV2)
+        (4,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV4)
+        (8,  adf4350_regs_t::RF_DIVIDER_SELECT_DIV8)
+        (16, adf4350_regs_t::RF_DIVIDER_SELECT_DIV16)
+    ;
+
+    double actual_freq, pfd_freq;
+    double ref_freq = self_base->get_iface()->get_clock_rate(unit);
+    int R=0, BS=0, N=0, FRAC=0, MOD=0;
+    int RFdiv = 1;
+    adf4350_regs_t::reference_divide_by_2_t T     = adf4350_regs_t::REFERENCE_DIVIDE_BY_2_DISABLED;
+    adf4350_regs_t::reference_doubler_t     D     = adf4350_regs_t::REFERENCE_DOUBLER_DISABLED;    
+
+    //Reference doubler for 50% duty cycle
+    // if ref_freq < 12.5MHz enable regs.reference_divide_by_2
+    if(ref_freq <= 12.5e6) D = adf4350_regs_t::REFERENCE_DOUBLER_ENABLED;
+
+    //increase RF divider until acceptable VCO frequency
+    //start with target_freq*2 because mixer has divide by 2
+    double vco_freq = target_freq;
+    while (vco_freq < 2.2e9) {
+        vco_freq *= 2;
+        RFdiv *= 2;
+    }
+
+    //use 8/9 prescaler for vco_freq > 3 GHz (pg.18 prescaler)
+    adf4350_regs_t::prescaler_t prescaler = vco_freq > 3e9 ? adf4350_regs_t::PRESCALER_8_9 : adf4350_regs_t::PRESCALER_4_5;
+
+    /*
+     * The goal here is to loop though possible R dividers,
+     * band select clock dividers, N (int) dividers, and FRAC 
+     * (frac) dividers.
+     *
+     * Calculate the N and F dividers for each set of values.
+     * The loop exists when it meets all of the constraints.
+     * The resulting loop values are loaded into the registers.
+     *
+     * from pg.21
+     *
+     * f_pfd = f_ref*(1+D)/(R*(1+T))
+     * f_vco = (N + (FRAC/MOD))*f_pfd
+     *    N = f_vco/f_pfd - FRAC/MOD = f_vco*((R*(T+1))/(f_ref*(1+D))) - FRAC/MOD
+     * f_rf = f_vco/RFdiv)
+     * f_actual = f_rf/2
+     */
+    for(R = 1; R <= 1023; R+=1){
+        //PFD input frequency = f_ref/R ... ignoring Reference doubler/divide-by-2 (D & T)
+        pfd_freq = ref_freq*(1+D)/(R*(1+T));
+
+        //keep the PFD frequency at or below 25MHz (Loop Filter Bandwidth)
+        if (pfd_freq > 25e6) continue;
+
+        //ignore fractional part of tuning
+        N = int(std::floor(vco_freq/pfd_freq));
+
+        //keep N > minimum int divider requirement
+        if (N < prescaler_to_min_int_div[prescaler]) continue;
+
+        for(BS=1; BS <= 255; BS+=1){
+            //keep the band select frequency at or below 100KHz
+            //constraint on band select clock
+            if (pfd_freq/BS > 100e3) continue;
+            goto done_loop;
+        }
+    } done_loop:
+
+    //Fractional-N calculation
+    MOD = 4095; //max fractional accuracy
+    FRAC = int((vco_freq/pfd_freq - N)*MOD);
+
+    //Reference divide-by-2 for 50% duty cycle
+    // if R even, move one divide by 2 to to regs.reference_divide_by_2
+    if(R % 2 == 0){
+        T = adf4350_regs_t::REFERENCE_DIVIDE_BY_2_ENABLED;
+        R /= 2;
+    }
+
+    //actual frequency calculation
+    actual_freq = double((N + (double(FRAC)/double(MOD)))*ref_freq*(1+int(D))/(R*(1+int(T)))/RFdiv);
+
+    UHD_LOGV(often)
+        << boost::format("SBX Intermediates: ref=%0.2f, outdiv=%f, fbdiv=%f") % (ref_freq*(1+int(D))/(R*(1+int(T)))) % double(RFdiv*2) % double(N + double(FRAC)/double(MOD)) << std::endl
+        << boost::format("SBX tune: R=%d, BS=%d, N=%d, FRAC=%d, MOD=%d, T=%d, D=%d, RFdiv=%d, LD=%d"
+            ) % R % BS % N % FRAC % MOD % T % D % RFdiv % self_base->get_locked(unit)<< std::endl
+        << boost::format("SBX Frequencies (MHz): REQ=%0.2f, ACT=%0.2f, VCO=%0.2f, PFD=%0.2f, BAND=%0.2f"
+            ) % (target_freq/1e6) % (actual_freq/1e6) % (vco_freq/1e6) % (pfd_freq/1e6) % (pfd_freq/BS/1e6) << std::endl;
+
+    //load the register values
+    adf4350_regs_t regs;
+
+    if ((unit == dboard_iface::UNIT_TX) and (actual_freq == sbx_tx_lo_2dbm.clip(actual_freq))) 
+        regs.output_power = adf4350_regs_t::OUTPUT_POWER_2DBM;
+    else
+        regs.output_power = adf4350_regs_t::OUTPUT_POWER_5DBM;
+
+    regs.frac_12_bit = FRAC;
+    regs.int_16_bit = N;
+    regs.mod_12_bit = MOD;
+    regs.prescaler = prescaler;
+    regs.r_counter_10_bit = R;
+    regs.reference_divide_by_2 = T;
+    regs.reference_doubler = D;
+    regs.band_select_clock_div = BS;
+    UHD_ASSERT_THROW(rfdivsel_to_enum.has_key(RFdiv));
+    regs.rf_divider_select = rfdivsel_to_enum[RFdiv];
+
+    //write the registers
+    //correct power-up sequence to write registers (5, 4, 3, 2, 1, 0)
+    int addr;
+
+    for(addr=5; addr>=0; addr--){
+        UHD_LOGV(often) << boost::format(
+            "SBX SPI Reg (0x%02x): 0x%08x"
+        ) % addr % regs.get_reg(addr) << std::endl;
+        self_base->get_iface()->write_spi(
+            unit, spi_config_t::EDGE_RISE,
+            regs.get_reg(addr), 32
+        );
+    }
+
+    //return the actual frequency
+    UHD_LOGV(often) << boost::format(
+        "SBX tune: actual frequency %f Mhz"
+    ) % (actual_freq/1e6) << std::endl;
+    return actual_freq;
+}
+
diff --git a/host/lib/usrp/dboard/db_sbx_version4.cpp b/host/lib/usrp/dboard/db_sbx_version4.cpp
new file mode 100644
index 000000000..ea0acb699
--- /dev/null
+++ b/host/lib/usrp/dboard/db_sbx_version4.cpp
@@ -0,0 +1,189 @@
+//
+// 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 "adf4351_regs.hpp"
+#include "db_sbx_common.hpp"
+
+
+using namespace uhd;
+using namespace uhd::usrp;
+using namespace boost::assign;
+
+/***********************************************************************
+ * Structors
+ **********************************************************************/
+sbx_xcvr::sbx_version4::sbx_version4(sbx_xcvr *_self_sbx_xcvr) {
+    //register the handle to our base SBX class
+    self_base = _self_sbx_xcvr;
+}
+
+
+sbx_xcvr::sbx_version4::~sbx_version4(void){
+    /* NOP */
+}
+
+
+/***********************************************************************
+ * Tuning
+ **********************************************************************/
+double sbx_xcvr::sbx_version4::set_lo_freq(dboard_iface::unit_t unit, double target_freq) {
+    UHD_LOGV(often) << boost::format(
+        "SBX tune: target frequency %f Mhz"
+    ) % (target_freq/1e6) << std::endl;
+
+    //clip the input
+    target_freq = sbx_freq_range.clip(target_freq);
+
+    //map prescaler setting to mininmum integer divider (N) values (pg.18 prescaler)
+    static const uhd::dict<int, int> prescaler_to_min_int_div = map_list_of
+        (0,23) //adf4351_regs_t::PRESCALER_4_5
+        (1,75) //adf4351_regs_t::PRESCALER_8_9
+    ;
+
+    //map rf divider select output dividers to enums
+    static const uhd::dict<int, adf4351_regs_t::rf_divider_select_t> rfdivsel_to_enum = map_list_of
+        (1,  adf4351_regs_t::RF_DIVIDER_SELECT_DIV1)
+        (2,  adf4351_regs_t::RF_DIVIDER_SELECT_DIV2)
+        (4,  adf4351_regs_t::RF_DIVIDER_SELECT_DIV4)
+        (8,  adf4351_regs_t::RF_DIVIDER_SELECT_DIV8)
+        (16, adf4351_regs_t::RF_DIVIDER_SELECT_DIV16)
+        (32, adf4351_regs_t::RF_DIVIDER_SELECT_DIV16)
+        (64, adf4351_regs_t::RF_DIVIDER_SELECT_DIV16)
+    ;
+
+    double actual_freq, pfd_freq;
+    double ref_freq = self_base->get_iface()->get_clock_rate(unit);
+    int R=0, BS=0, N=0, FRAC=0, MOD=0;
+    int RFdiv = 1;
+    adf4351_regs_t::reference_divide_by_2_t T     = adf4351_regs_t::REFERENCE_DIVIDE_BY_2_DISABLED;
+    adf4351_regs_t::reference_doubler_t     D     = adf4351_regs_t::REFERENCE_DOUBLER_DISABLED;    
+
+    //Reference doubler for 50% duty cycle
+    // if ref_freq < 12.5MHz enable regs.reference_divide_by_2
+    if(ref_freq <= 12.5e6) D = adf4351_regs_t::REFERENCE_DOUBLER_ENABLED;
+
+    //increase RF divider until acceptable VCO frequency
+    //start with target_freq*2 because mixer has divide by 2
+    double vco_freq = target_freq;
+    while (vco_freq < 2.2e9) {
+        vco_freq *= 2;
+        RFdiv *= 2;
+    }
+
+    //use 8/9 prescaler for vco_freq > 3 GHz (pg.18 prescaler)
+    adf4351_regs_t::prescaler_t prescaler = vco_freq > 3e9 ? adf4351_regs_t::PRESCALER_8_9 : adf4351_regs_t::PRESCALER_4_5;
+
+    /*
+     * The goal here is to loop though possible R dividers,
+     * band select clock dividers, N (int) dividers, and FRAC 
+     * (frac) dividers.
+     *
+     * Calculate the N and F dividers for each set of values.
+     * The loop exists when it meets all of the constraints.
+     * The resulting loop values are loaded into the registers.
+     *
+     * from pg.21
+     *
+     * f_pfd = f_ref*(1+D)/(R*(1+T))
+     * f_vco = (N + (FRAC/MOD))*f_pfd
+     *    N = f_vco/f_pfd - FRAC/MOD = f_vco*((R*(T+1))/(f_ref*(1+D))) - FRAC/MOD
+     * f_rf = f_vco/RFdiv)
+     * f_actual = f_rf/2
+     */
+    for(R = 1; R <= 1023; R+=1){
+        //PFD input frequency = f_ref/R ... ignoring Reference doubler/divide-by-2 (D & T)
+        pfd_freq = ref_freq*(1+D)/(R*(1+T));
+
+        //keep the PFD frequency at or below 25MHz (Loop Filter Bandwidth)
+        if (pfd_freq > 25e6) continue;
+
+        //ignore fractional part of tuning
+        N = int(std::floor(vco_freq/pfd_freq));
+
+        //keep N > minimum int divider requirement
+        if (N < prescaler_to_min_int_div[prescaler]) continue;
+
+        for(BS=1; BS <= 255; BS+=1){
+            //keep the band select frequency at or below 100KHz
+            //constraint on band select clock
+            if (pfd_freq/BS > 100e3) continue;
+            goto done_loop;
+        }
+    } done_loop:
+
+    //Fractional-N calculation
+    MOD = 4095; //max fractional accuracy
+    FRAC = int((vco_freq/pfd_freq - N)*MOD);
+
+    //Reference divide-by-2 for 50% duty cycle
+    // if R even, move one divide by 2 to to regs.reference_divide_by_2
+    if(R % 2 == 0){
+        T = adf4351_regs_t::REFERENCE_DIVIDE_BY_2_ENABLED;
+        R /= 2;
+    }
+
+    //actual frequency calculation
+    actual_freq = double((N + (double(FRAC)/double(MOD)))*ref_freq*(1+int(D))/(R*(1+int(T)))/RFdiv);
+
+    UHD_LOGV(often)
+        << boost::format("SBX Intermediates: ref=%0.2f, outdiv=%f, fbdiv=%f") % (ref_freq*(1+int(D))/(R*(1+int(T)))) % double(RFdiv*2) % double(N + double(FRAC)/double(MOD)) << std::endl
+        << boost::format("SBX tune: R=%d, BS=%d, N=%d, FRAC=%d, MOD=%d, T=%d, D=%d, RFdiv=%d, LD=%d"
+            ) % R % BS % N % FRAC % MOD % T % D % RFdiv % self_base->get_locked(unit)<< std::endl
+        << boost::format("SBX Frequencies (MHz): REQ=%0.2f, ACT=%0.2f, VCO=%0.2f, PFD=%0.2f, BAND=%0.2f"
+            ) % (target_freq/1e6) % (actual_freq/1e6) % (vco_freq/1e6) % (pfd_freq/1e6) % (pfd_freq/BS/1e6) << std::endl;
+
+    //load the register values
+    adf4351_regs_t regs;
+
+    if ((unit == dboard_iface::UNIT_TX) and (actual_freq == sbx_tx_lo_2dbm.clip(actual_freq))) 
+        regs.output_power = adf4351_regs_t::OUTPUT_POWER_2DBM;
+    else
+        regs.output_power = adf4351_regs_t::OUTPUT_POWER_5DBM;
+
+    regs.frac_12_bit = FRAC;
+    regs.int_16_bit = N;
+    regs.mod_12_bit = MOD;
+    regs.prescaler = prescaler;
+    regs.r_counter_10_bit = R;
+    regs.reference_divide_by_2 = T;
+    regs.reference_doubler = D;
+    regs.band_select_clock_div = BS;
+    UHD_ASSERT_THROW(rfdivsel_to_enum.has_key(RFdiv));
+    regs.rf_divider_select = rfdivsel_to_enum[RFdiv];
+
+    //write the registers
+    //correct power-up sequence to write registers (5, 4, 3, 2, 1, 0)
+    int addr;
+
+    for(addr=5; addr>=0; addr--){
+        UHD_LOGV(often) << boost::format(
+            "SBX SPI Reg (0x%02x): 0x%08x"
+        ) % addr % regs.get_reg(addr) << std::endl;
+        self_base->get_iface()->write_spi(
+            unit, spi_config_t::EDGE_RISE,
+            regs.get_reg(addr), 32
+        );
+    }
+
+    //return the actual frequency
+    UHD_LOGV(often) << boost::format(
+        "SBX tune: actual frequency %f Mhz"
+    ) % (actual_freq/1e6) << std::endl;
+    return actual_freq;
+}
+