>On a related note: what is the maximum voltage on RA4 when VDD is at zero
>volts?  Is there any "safe" current level [e.g. if I were to connect RA4
>to +5 through a 1M resistor while VDD was at zero, would that be safe?
>What if it were a 10K resistor?  What if it were a Zerohm(tm) "resistor"?]

The trouble with power being applied to any pin while Vdd is zero, is
that the device can still remain in a powered up state. Current flows
into the IO pin, through the protection diode, and back to the chip's
internal Vdd rail. Therefor a 10K resistor would provide 440uA of
current which is more than enough to power a PIC on LP mode. As the
chip may not power down correctly because of this current flow, it
may not start up reliably as well.

Tony


Just when I thought I knew it all,
I learned that I didn't.