Hi! > An external timebase has been implemented in two ways. The most > desireable is via the kernel and an appropriate shared memory device > driver.
Hmm, I guess, that would mess up the whole kernel and it's time keeping. If not necessary, I would like to avoid generating more troubles than necessary. > An alternative way is to used a driver such as the KSI/Odetics > TPRO refclock driver. There might even be a refclock driver for the old > TrueTime TT-560, although Symmetricom gutted the TT product line when > they ate them. > Ok, thanks for the hint, I'll have a look at that code. > There are numberous gremlins in your project. If all you want to do is > stabilize the motherboard timer oscillator, poke the timer pin with a > stable stignal and let the kernel/NTP feedback loop do the discipline > and interpolation. As mentioned in my other posting from today, my final goal is to run NTP with hardware timestamp support to have a fair comparison to IEEE 1588 for my PhD. (I guess, there won't be much difference, concerning accuracy) Unfortunately, I couldn't find any implementations (maybe there is a good reason ...?) so I'm trying it on my own. I know how to get the timestamps from the network card into NTP but I need the daemon to discipline the clock on the card to make it somehow useful. > If you want to do frequency discipline, you will need > to engineer some critical loop parameters. See Chapter 4 in my book. > I'll certainly have, since I expect to run in control loop tuning problems. Kind Regards, Patrick _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
