On Sun, 4 Sept 2022 at 07:24, Hamilton Alex <alexzanda...@gmail.com> wrote:
> I think i have found the cause. > my DPLL is accessed by SPI, though frequency adjustment is only writing to > one register, it takes about 1.2 seconds! > You can try increasing the intervals, "xxxSyncInterval". It will take longer to synchronize, but you will be able to use your slow SPI. Erez > so everytime after servo calculates the the ppb, it takes 1.2 seconds to > make ppb change, during that time, the master offset > has already shifted a lot. that's why the result is totally different > from simulation. > > Thanks > Alex > > Hamilton Alex <alexzanda...@gmail.com> 于2022年9月3日周六 12:54写道： > >> what i have verified is: >> 1. Use syncE mode, so don't need to adjust frequency, use linuxptp to >> adjust phase offset only, everything works fine. >> 2. manually test frequency adjust function and it works well, let the >> board run in freerun mode, can manually adjust frequency and phase to make >> phase offset within +/- 10NS. >> 3. use linuxptp servo for frequency adjustment, it can't converge. >> >> Richard Cochran <richardcoch...@gmail.com> 于2022年9月3日周六 10:57写道： >> >>> On Sat, Sep 03, 2022 at 08:09:14AM +0800, Hamilton Alex wrote: >>> >>> > I didn't use custom vendor linux driver, Zarlink provided steps to >>> adjust >>> > its DPLL frequency and I implement >>> > it by my self. >>> >>> Oh, well, in that case, probably your own custom driver has a bug. >>> >>> Good luck, >>> Richard >>> >> _______________________________________________ > Linuxptp-devel mailing list > Linuxptp-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linuxptp-devel >
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