On Tue, Oct 21, 2014 at 6:58 AM, Simon Marsh > How do you map the timer counter value in to a PPS timestamp ? > (that is, how do you turn the HW counter value in to what the OS thought the > time was when the event occured ?)
He is running NTP. NTP's job is it keep the system time in sync with a number of "reference clocks". The 1PPS from a GPS makes a good reference clock. It does this by adjusting the RATE of the system clock to not gain or loose vs. a set of reference clocks over time. The algorithm is not simple. The weak link is that the timing is done in software and in the real world the accuracy is a few microseconds. -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
