Lpc2000

> An interesting experiment might be to compare the response of using an
> external interrupt pin set as a FIQ.  It seems it should be slower than
> polling FIOPIN, but curious as to the results.
>

I recall reading somewhere about the timing in this situation.  If I
remember correctly, it can potentially be a very broad range of clock
cycles (mostly depending on the instruction being executed at the
moment).  I didnt even try because I need very deterministic code.  I
cant have my response time in one situation, too much different than
another situation.

Even so, I will see if I cant get you some numbers for the jump to the
FIQ routine for you.  Besides polling the FIOPIN, I tried FIQs in a
little different way.  I set up the external interrupt triggered FIQ
but I didnt enable FIQs.  The VICFIQStatus register will still change,
so I polled that.  The only reason why I tried was for the built in
edge detection on external interrupts.  I cant remember the timing
values, I will see if I can rerun that test also.

Vern