fmc-tdc-tstamp displays timestamps with ps part more than 1s
fmc-tdc-tstamp
every second displays timestamps with ps part more than 1s
sudo ../fmc-tdc-tstamp -L 2 -c 0 | grep ts
ts 1642181939s 999197706736ps
ts 1642181939s 1000197706644ps <-------------------
ts 1642181939s 1001197706634ps <-------------------
ts 1642181940s 002197706705ps
TDC card was connected directly to a fine delay, which was producing 1kHz pulses. The same behavior was reproduced with other frequencies.
fmc-fdelay-status -d 0x12
Input : enabled
timestamping: enabled
50 Ohm termination: disabled
Channel 1: pulse generator mode (triggered)
start at: 1642181718:000,100,000,000 ps
pulse width: 0:000,001,000,000 ps
repeat: infinite
period: 0:001,000,000,000 ps
Channel 2: disabled
Channel 3: disabled
Channel 4: disabled
Probably raw timestamps coming from HW are not normalized.