[time-nuts] Net4501

[Chris Albertson]

If you look at PHK's code in FreeBSD this is what is done. The PPS signal
> gates the timer, so no interrupt is involved in the time stamp precision.
> But yes, it would be interesting to do something on a FPGA. Unfortunately I
> wouldn't be able to get to anything like that myself in this lifetime.
>

Does the hardware on the NET4501 allow this?  Standard PC hardware doesn't.
  I thought the 4501 used a "Pentium" CPU and the counter would be internal
to the CPU and you'd have to read out the count in an interrupt handler.
I have read the Linux code for this, which I hear is about the same as BSD.
  But then I read the common x86 achitecture.



-- 

Chris Albertson
Redondo Beach, California