On 2011-10-17, Hal Murray <[email protected]> wrote: > In article <[email protected]>, > unruh <[email protected]> writes: > >>In fact it is really hard for a computer to keep to 1us accuracy because >>of the delays in interrupt processing. > > It's not the delay that is the problem. It's simple to correct for a > fixed delay. (at least in theory) The problem is variations in the delay.
Agreed, if only you had some way of knowing what the delay was. But as you point out, if you did, it would not really be a problem (just as the light travel down the cable from the GPS to the computer is not really a problem since it can be calculated easily and thus fixed. Also, it is usually much much smaller than the other delays.) > > Jitter can easily be caused by cache faults or jitter in finishting the > processing of the current instruction, or having interrupts disabled. > (There are probably other sources.) _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
