Ulrich Windl wrote on linux-kernel:
I’ve updated the PPSkit for Linux 2.0.36. This is an important
update, because I finally tamed the 200us jitter on the PPS signal
that prevented any reasonable work! I strongly advise any
PPSkit-0.3 users to update. (Linux 2.2 does not have this
problem)
If you want to verify the jitter quick, easy and dirty, you
could use “enable_pps -j -k Remaining problems are the receive
timestamps wandering around, and finally wrapping at the end of a
time tick, and sometime no PPS pulses are detected on the first
open after reboot (I’m using loadable modules for the serial
port).
Along with this fix come a few other cleanups (similar to those
in the 0.5 version)
So, as usual, here is the NEWS and the LSM.
Enjoy,
Ulrich
P.S.: Just in time for the CeBIT 😉
NEWS for 0.3.9
- Stole a piece of Pentium timing code from Linux-2.2 to avoid
the jitter of 200us that makes the PPS signal unusable. This fix
replaces the patch for “Completely Mad Time”. - Updated `enable_pps.c’ from PPSkit-0.6. Updated example
configuration file for xntpd (3-5.93, used for testing) - Improved accuracy of `hardware_pps()’ by getting the correct
time. - Made `TIME_ERROR’ less sticky, and relax some restrictions of
`adjtimex()’. Ignore the bug that has to do with
“STA_FREQHOLD|STA_FLL”. - This release is actually a branch release, because the actual
development is at 0.6 (Linux 2.2) now. Don’t expect exciting new
stuff here.
Begin3
Title: PPSkit
Version: 0.3.9
Entered-date: 1999-03-14
Description: NTP PPS support (and other time patches) for Linux 2.0.36+
(kernel patch, documentation, test programs)
Keywords: NTP, PPS, kernel, xntp, time, pulse-per-second,
synchronization, adjtimex
Author: Ulrich.Windl@rz.uni-regensburg.de (Ulrich Windl)
Maintained-by: Ulrich.Windl@rz.uni-regensburg.de (Ulrich Windl)
Primary-site: linux.kernel.org /pub/linux/daemons/ntp/PPS
37kB PPSkit-0.3.9.tar.gz
Alternate-site:
Original-site: pcphy4.physik.uni-regensburg.de /pub/wiu09524/PPS
PPSkit-0.3.9.tar.gz
Platform: RS232-compatible precision pulse-per-second with an error
less than 200ppm (0.0002%, 0.2ms)
Copying-policy: GPL, but payment welcome!
End