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diff --git a/host/docs/usrp_b1xx.rst b/host/docs/usrp_b1xx.rst new file mode 100644 index 000000000..75b901a86 --- /dev/null +++ b/host/docs/usrp_b1xx.rst @@ -0,0 +1,58 @@ +======================================================================== +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" |