Hi Bob,

> I am writing code to use the PIC chip as a classic embedded controller.
> One of the commands I would like to implement is a remote reset.  This
> would allow the controlling system to issue a command that would tell the
> PIC to restart and re initialize itself.
>
> Is there an easy way to reset the PIC processor from a running application ???
>
> The PIC in this particular endeavor is a 16C73A...

I have used a I/O pin in the past to reset PICs and Parallax Stamps.

Just connect your remaining pin to the _MCLR pin and when you want
to reset you just drive the pin to an output and then write a
zero to it.  This is very effective and clears the condition on the
pin when the chip has reset as the pins all change to inputs
after the reset.

The other alternative of letting the watchdog run-out by turning
off interrupts and running in a tight loop would cause a reset
from about 20 ms to 2 seconds later (depending on the watchdog
prescaler).  This requires you to have the watchdog fuse enabled
and also the reset will not be exactly the same as a MCLR reset.
You also need to service the watchdog in the rest of your code.
This option is not available with most of the preprogrammed interpreter
chips like the Stamps which is why I used the first method above.

Perhaps better yet is to use a pin to short the supply rail to ground
with the help of an external transistor that will cause a genuine
cold reset.  This might be requiired by some of the periferals
on some of the early silicon that had some quirks where a WD
or MCLR reset were nor enough to clear a stuck periferal (UART
I think was the problem one)

Cheers
--
Kalle Pihlajasaari   kalle@ip.co.za   http://www.ip.co.za/ip
Interface Products   P O Box 15775, DOORNFONTEIN, 2028, South Africa
+ 27 (11) 402-7750   Fax: 402-7751    http://www.ip.co.za/people/kalle

DonTronics, Silicon Studio and Wirz Electronics uP Product Dealer