Yo Achim! On Sun, 12 Aug 2018 09:33:36 +0200 Achim Gratz via devel <devel@ntpsec.org> wrote:
> > The results are an average PPS jitter of 222 ns!
>
> Well, yes -- if you measure and eliminate the interrupt latency, which
> by far dominates the jitter in the normal PPS processing, then the
> residual jitter goes down.
I'll take it! One good step at a time.
> The missed opportunity with this implementation is that you could
> actually measure both the raw system clock frequency and the (NTP
> corrected) phase independently and thus improve the convergence of the
> FLL/PLL algorithm significantly by using both the rising and falling
> edge measurement.
The ntpd convergence has always bugged me a lot. But since most time
nuts never power down their gear they ignore this part of the problem.
> It's also unfortunate that apparently no attempt was made to
Suggest that for his PhD thesis.
I'll be happy if we can get a copy of his code.
RGDS
GARY
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