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diff --git a/host/docs/gpsdo_x3x0.rst b/host/docs/gpsdo_x3x0.rst deleted file mode 100644 index 0d4d31f3b..000000000 --- a/host/docs/gpsdo_x3x0.rst +++ /dev/null @@ -1,82 +0,0 @@ -======================================================================== -UHD - Internal GPSDO Application Notes (USRP-X3x0 Models) -======================================================================== - -.. contents:: Table of Contents - -This application note describes the use of the board-mounted GPS Disciplined OCXO, -as used with the USRP X300/X310. For information regarding the GPSDO that is -compatible with the USRP N2xx or E1xx, please see: - -`USRP-N2x0/E1x0 Internal GPSDO Device Manual <./gpsdo.html>`_ - ------------------------------------------------------------------------- -Specifications ------------------------------------------------------------------------- -* **Receiver type**: 50 channel with WAAS, EGNOS, MSAS -* **10 MHz ADEV**: 5e-11 over >24h -* **1PPS RMS jitter**: <50ns 1-sigma -* **Holdover**: <20us over 3h - -**Phase noise**: - -+------------+------------+ -| | OCXO | -+============+============+ -| **1Hz** | -75dBc/Hz | -+------------+------------+ -| **10Hz** | -110dBc/Hz | -+------------+------------+ -| **100Hz** | -132dBc/Hz | -+------------+------------+ -| **1kHz** | -142dBc/Hz | -+------------+------------+ -| **10kHz** | -145dBc/Hz | -+------------+------------+ -| **100kHz** | -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. |