I've seen two answers to dennis's question so far and generally I would
agree. Your first answer mentioned 16f84 self reprogramming problems
which I will remember. Here is my opinion for what it is worth:

If you realy need high volume AND are trying hard to reduce cost AND you
want to use a  NON brownout protected PIC (they do come with brownout
protection now) AND your application is not a super critical one then:

1) Do try to have the reset pin perform a usefull function for your
program; most ram will still carry your operating parameters (except
prog cntr) after an MCLR.

2) Do periodically REinitialise TMRO, baud rate, I/O direction etc as
much as possible like a genuine POR reset.

3) Do enable the watchdog timer.

4) Do check your code to be assured that no sub loops may become
un-exit-able if ram contents become corrupted.

5) Do use some of your extra memory to insert "goto *" (here    goto    here)
loops in between code modules; this will trigger the WDT if the PIC PCL
incs blindly past the real code jumps.

6) Don't use CLRWDT instructions too freely.

Hope this helps,

Graham Daniel:end

Dennis Plunkett wrote:
>
> At 07:09 AM 29/04/98 -0400, you wrote:
> >Piclisters!
> >I am currently using DS1233 econo-resets that hold the MCLR line low for
> >approx. 15ms, just after power-up.  My PIC application is automotive.  I
> >have a very clean 5v regulator supply.  Slow power-up is not a problem.
> >
> >My question is:  Is this uP supervisor necessary w/ the PIC (16c76, 16c63,
> >and 16F84) ????
> >
> >Cya-
> >                         6500
> >                              7000
> >Dave Celsnak                    ___7500
> >                               / /     8000     (Shift!)
> >                             /-/
> >                           / /              RPM
> >                         / /
> >                       / /
> >
> >
>
> Slow power up may not be your problem in automotive, but brown out is. The
> GM spec puts the 12V supply down to 4Volts under cranking condtions. If the
> support cicruits connected to the PIC have the same supply rating, then
> there is not a problem. I do think that a reset chip should be used, as
> there are other considerations such as the location of the target device in
> the auto and what other things are active (On the same loom)
>
> Dennis