[ntp:questions] Re: Linux PPS triggering with NMEA

David Schwartz davids at webmaster.com
Mon May 9 21:52:14 UTC 2005


"Bjorn Gabrielsson" <bg at lysator.liu.se> wrote in message 
news:m3acn4ozpe.fsf at lysator.liu.se...

> I know what TIOCMIWAIT gives. Is there a user-space function that can
> return time with better than than the 1us resolution that
> gettimeofday() gives?

    No. But unless you have some specialized hardware, you're just kidding 
yourself if you think you can get more than that. Even with a PPS input 
accurate to 200nS and the PPS kernel patches, accuracy is still only about 3 
microseconds.

    DS





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