Bob Blick wrote:
>=20
> I'm needing to detect ten external interrupts from pulses that can be
> very short so I won't be able to respond to a port-wide interrupt fast
> enough to poll the port for the interrupting pin or pins.
>=20
> I could use a one-shot or buskeeper circuit with diode before it but if
> I could find a micro that had separate interrupt vectors or built-in
> pin hold I could reduce parts count.

The interrupt-on-change facility on enhanced mid-range PICs (16F1*) has a
separate edge detector (each configurable as falling or rising) for each
pin, with per-pin status flags.  Note that is different to (much more
capable) than the old PIC port-change facility that you might be used to,
where you had to poll to see which pin on the port changed.
It should do what you want, fast enough, with no need for polling.

The PIC16F1828 has ten IOC pins, for example.

Regards,
David Meiklejohn
www.gooligum.com.au





--=20
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