8 files changed, 89 insertions, 11 deletions
diff --git a/host/docs/CMakeLists.txt b/host/docs/CMakeLists.txt
index 17744db7d..fa6e98918 100644
--- a/host/docs/CMakeLists.txt
+++ b/host/docs/CMakeLists.txt
@@ -26,6 +26,7 @@ SET(manual_sources
     coding.rst
     dboards.rst
     gpsdo.rst
+    gpsdo_b2x0.rst
     general.rst
     images.rst
     stream.rst
diff --git a/host/docs/build.rst b/host/docs/build.rst
index 00f79aaaa..5512e71ae 100644
--- a/host/docs/build.rst
+++ b/host/docs/build.rst
@@ -64,7 +64,7 @@ LibUSB
 * **Minimum Version:** 1.0
 * **Usage:** build time + runtime (optional)
 * **Download URL:** http://sourceforge.net/projects/libusb/files/libusb-1.0/
-* **Download URL (Windows binaries):** http://www.libusb.org/wiki/windows_backend#LatestBinarySnapshots
+* **Download URL (Windows):** https://github.com/libusbx/libusbx
 
 ^^^^^^^^^^^^^^^^
 Python
@@ -169,7 +169,7 @@ Generate the project with CMake
 * Click "Generate", and a project file will be created in the build directory.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-LibUSB CMake notes
+LibUSB notes
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 On Windows, CMake does not have the advantage of **pkg-config**,
 so we must manually tell CMake how to locate the LibUSB header and lib.
@@ -182,6 +182,8 @@ so we must manually tell CMake how to locate the LibUSB header and lib.
 
 * Check the box to enable USB support, click "Configure" and "Generate".
 
+**Note:** On Windows, LibUSBx is required to use most USB3 controllers.
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Build the project in MSVC
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/host/docs/gpsdo.rst b/host/docs/gpsdo.rst
index 1e9019a0f..1cf1dae29 100644
--- a/host/docs/gpsdo.rst
+++ b/host/docs/gpsdo.rst
@@ -1,5 +1,5 @@
 ========================================================================
-UHD - Internal GPSDO Application Notes
+UHD - Internal GPSDO Application Notes (USRP-N2x0/E1X0 Models)
 ========================================================================
 
 .. contents:: Table of Contents
diff --git a/host/docs/gpsdo_b2x0.rst b/host/docs/gpsdo_b2x0.rst
new file mode 100644
index 000000000..bca10e99a
--- /dev/null
+++ b/host/docs/gpsdo_b2x0.rst
@@ -0,0 +1,80 @@
+========================================================================
+UHD - Internal GPSDO Application Notes (USRP-B2X0 Models)
+========================================================================
+
+.. contents:: Table of Contents
+
+This application note describes the use of integrated GPS-disciplined
+oscillators with Ettus Research USRP devices. It pertains specifically
+to the Jackson Labs LC_XO device unless noted otherwise.
+
+------------------------------------------------------------------------
+Specifications
+------------------------------------------------------------------------
+* **Receiver type**: 50 channel with WAAS, EGNOS, MSAS
+* **10MHz ADEV**: 5e-11 over >24h
+* **1PPS RMS jitter**: <50ns 1-sigma
+* **Holdover**: <20us over 3h
+
+**Phase noise**:
+
++------------+-------------+------------+
+|            |     TCXO    |    OXCO    |
++============+=============+============+
+| **1Hz**    | -65dBc/Hz   | -75dBc/Hz  |
++------------+-------------+------------+
+| **10Hz**   |  -102dBc/Hz | -110dBc/Hz |
++------------+-------------+------------+
+| **100Hz**  | -132dBc/Hz  | -132dBc/Hz |
++------------+-------------+------------+
+| **1kHz**   | -148dBc/Hz  | -142dBc/Hz |
++------------+-------------+------------+
+| **10kHz**  | -152dBc/Hz  | -145dBc/Hz |
++------------+-------------+------------+
+| **100kHz** | <-155dBc/Hz | -150dBc/Hz |
++------------+-------------+------------+
+
+**Antenna Types:**
+
+The GPSDO is capable of supplying a 3V for active GPS antennas or supporting passive antennas.
+
+------------------------------------------------------------------------
+Installation Instructions
+------------------------------------------------------------------------
+To install the GPSDO, you must insert it into the slot on the board
+near the 10 MHz Reference SMA. Keep in mind that the two sides of the
+GPSDO have a different number of pins. When inserting the GPSDO, make
+sure to press down firmly and evenly. When turning on the USRP B2X0 device,
+a green LED should illuminate on the GPSDO. This signifies that the unit
+has successfully been placed.
+
+**NOTE: The pins on the GPSDO are very fragile. Be sure to press down
+evenly, or the pins may bend or break. Once the GPSDO is in place,
+we very highly discourage further removal, as this also risks damaging
+the pins.**
+
+------------------------------------------------------------------------
+Using the GPSDO in Your Application
+------------------------------------------------------------------------
+By default, if a GPSDO is detected at startup, the USRP will be configured
+to use it as a frequency and time reference. The internal VITA timestamp
+will be initialized to the GPS time, and the internal oscillator will be
+phase-locked to the 10MHz GPSDO reference. If the GPSDO is not locked to
+satellites, the VITA time will not be initialized.
+
+GPS data is obtained through the **mboard_sensors** interface. To retrieve
+the current GPS time, use the **gps_time** sensor:
+
+::
+
+    usrp->get_mboard_sensor("gps_time");
+
+The returned value will be the current epoch time, in seconds since
+January 1, 1970. This value is readily converted into human-readable
+format using the **time.h** library in C, **boost::posix_time** in C++, etc.
+
+Other information can be fetched as well. You can query the lock status
+with the **gps_locked** sensor, as well as obtain raw NMEA sentences using
+the **gps_gprmc**, and **gps_gpgga** sensors. Location
+information can be parsed out of the **gps_gpgga** sensor by using **gpsd** or
+another NMEA parser.
diff --git a/host/docs/index.rst b/host/docs/index.rst
index 27523c139..65069059f 100644
--- a/host/docs/index.rst
+++ b/host/docs/index.rst
@@ -32,7 +32,8 @@ Application Notes
 * `Daughterboard Application Notes <./dboards.html>`_
 * `Transport Application Notes <./transport.html>`_
 * `Synchronization Application Notes <./sync.html>`_
-* `Internal GPSDO Application Notes <./gpsdo.html>`_
+* `Internal GPSDO Application Notes (USRP-N2X0/E1X0 Models) <./gpsdo.html>`_
+* `Internal GPSDO Application Notes (USRP-B2X0 Models) <./gpsdo_b2x0.html>`_
 * `Calibration Application Notes <./calibration.html>`_
 
 ^^^^^^^^^^^^^^^^^^^^^
diff --git a/host/docs/uhd_find_devices.1 b/host/docs/uhd_find_devices.1
index 7dc0dd470..08f9a789c 100644
--- a/host/docs/uhd_find_devices.1
+++ b/host/docs/uhd_find_devices.1
@@ -9,9 +9,6 @@ The UHD package is the universal hardware driver for Ettus Research
 products. The goal is to provide a host driver and API for
 current and future Ettus Research products. Users will be able to use
 the UHD driver standalone or with 3rd party applications.
-.LP
-Hardware supporting UHD drivers includes the Universal Software Radio
-Peripheral, or USRP, available in several models.
 .SH SYNOPSIS
 .B  uhd_find_devices [OPTIONS]
 .SH OPTIONS
diff --git a/host/docs/uhd_images_downloader.1 b/host/docs/uhd_images_downloader.1
index ece826cb5..28310dd37 100644
--- a/host/docs/uhd_images_downloader.1
+++ b/host/docs/uhd_images_downloader.1
@@ -7,9 +7,6 @@ products. The goal of the UHD is to provide a host driver and API for
 current and future Ettus Research products. Users will be able to use
 the UHD driver standalone or with 3rd party applications.
 .LP
-Hardware supporting UHD drivers includes the Universal Software Radio
-Peripheral, or USRP, available in several models.
-.LP
 This program installs the firmware and FPGA binaries from Ettus Research
 matching this UHD driver release onto the host system. If the uhd-images
 package is installed, there is no need to run this installer.
diff --git a/host/docs/uhd_usrp_probe.1 b/host/docs/uhd_usrp_probe.1
index 7e82bf99a..a6c7150ee 100644
--- a/host/docs/uhd_usrp_probe.1
+++ b/host/docs/uhd_usrp_probe.1
@@ -1,6 +1,6 @@
 .TH "uhd_usrp_probe" 1 "3.5.1" UHD "User Commands"
 .SH NAME
-uhd_usrp_probe \- Universal Hardware Driver Peripheral Report Utility
+uhd_usrp_probe \- USRP Hardware Driver Peripheral Report Utility
 .SH DESCRIPTION
 Report detailed information on UHD-supported Software Radio Peripherals
 attached by USB, network, or embedded configuration.