I've seen some odd behavior with timestamps for samples from the B210 being off by large fractions of a second from what I expected when setting the time to GPS time. I wrote a program (see attached) that uses get_time_last_pps() to attempt to validate that the time is being set correctly. I discovered that when using a master clock rate of 61.44 MHz, the time returned is sometimes off by a quarter second (see output from running below). At a master clock rate of 16 MHz, I don't see this issue. Testing was done with UHD 3.10.1.0. Is my program doing something wrong or is this is an issue with the B200?
time_test--args type=b200,master_clock_rate=61.44e6
linux; GNU C++ version 5.2.1 20150902 (Red Hat 5.2.1-2); Boost_106000;
UHD_003.010.001.000-0-unknown
Creating the usrp device with: type=b200,master_clock_rate=30.72e6...
-- Detected Device: B210
-- Operating over USB 3.
-- Detecting internal GPSDO.... Found an internal GPSDO: GPSTCXO , Firmware
Rev 0.929a
-- Initialize CODEC control...
-- Initialize Radio control...
-- Performing register loopback test... pass
-- Performing register loopback test... pass
-- Performing CODEC loopback test... pass
-- Performing CODEC loopback test... pass
-- Asking for clock rate 61.440000 MHz...
-- Actually got clock rate 61.440000 MHz.
-- Performing timer loopback test... pass
-- Performing timer loopback test... pass
Using Device: Single USRP:
Device: B-Series Device
Mboard 0: B210
RX Channel: 0
RX DSP: 0
RX Dboard: A
RX Subdev: FE-RX2
RX Channel: 1
RX DSP: 1
RX Dboard: A
RX Subdev: FE-RX1
TX Channel: 0
TX DSP: 0
TX Dboard: A
TX Subdev: FE-TX2
TX Channel: 1
TX DSP: 1
TX Dboard: A
TX Subdev: FE-TX1
Time set count 4 check 1/5: ERROR: Time difference at last PPS: 0.249037
Time set count 4 check 4/5: ERROR: Time difference at last PPS: 0.249999
Time set count 8 check 1/5: ERROR: Time difference at last PPS: 0.249999
time_test.cpp
Description: Binary data
smime.p7s
Description: S/MIME cryptographic signature
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