The lock up problem I have found is documented in the MicroChip data book,
basically if the MCLR does not stay in sync with Vdd then the chip will lockup.
I use an MC3064 reset chip to ensure proper operation, as well as using the
watchdog.

At 08:26 PM 1/26/98 +0100, you wrote:
>I have read somewhere that a PIC can lock up (latch-up?) beyond reset,
>needing a power-off to get back into a normal mode.
>For my (in-circuit) 16c84 programmer I'm considering to include a
>'power-short' feature for this kind of situation.
>Questions:
>- has anyone experienced such a lock-up where a reset is not sufficient
>- what caused it
>- does this situation ocur often enough to warrant a few extra components
>in my programmer
>
>regards,
>Wouter.
>
>

Thanks.


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