[time-nuts] Time stamping with a PICPET

[Chris Albertson]

I'm pretty certain the outer that the PPS interrupt handler reads in on the
CPU chip.   The counter counts nanoseconds but the lower digits are always
zero.  I don't think a PCI bus is involved


On Sun, Oct 27, 2013 at 7:08 PM, Dennis Ferguson <
dennis.c.ferguson at gmail.com> wrote:

>
> ...
> > The rules for things like PCI cover that case.  If you do something like
> > write to a register to clear an interrupt request, you have to follow it
> by a
> > read to that register or one close to it.

-- 

Chris Albertson
Redondo Beach, California