[ntp:questions] higher sync rates?

Terje Mathisen "terje.mathisen at tmsw.no" at psp2.ntp.org
Thu Jan 14 16:04:39 UTC 2010

Raptor Victor wrote:
> HI,
> I have written a reference clock driver which basically uses the
> refclock_timer function while communicating with the reference clock. Now my
> reference clock can provide more than one packet per secoind but the
> refclock_timer just accepts timecodes once per second. Thus my driver works
> fine when the reference clock is having a sync rate of 1/sec but higher sync
> rates i cant exploit. I tried to look in the source code but could not find
> how refclock_timer is controlled.
> Can someone please throw some light on the said issue that whether 1timecode
> per second is the maximum ntp can accept (i.e. save in the circular buffer )
> or can we adjust it manually too?

I think I have seen previous discussion where people have modified one 
of the GPS drivers to work in 5Hz, basically by taking the "best" sample 
(usually determined by being as early as possible, i.e. having the 
minimum interrupt latency), and then returning that to the ntpd core 
protocol engine.


- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

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