Startup is an issue--but so are false resets.
Had an engineer working for me once that thought the cap on MCLR was the
Holy Grail, and absolutely necessary to prevent false resets.
Your thoughts?
Kelly



At 09:17 AM 2/23/00 -0700, you wrote:
>At 08:07 AM 2/23/00 +0100, you wrote:
>>Hi,
>>for being correct, put a Schmitt-trigger or at least a CMOS buffer between
>>MCLR and that RC chain. PIC hates slowly increasing level on the MCLR pin!
>>
>>Regards,
>>Imre
>>
>
>Actually, the Mchp dataheet mentions using the R-C startup ckt
>"... (for slow Vdd powerup)". Apparently, the internal powerup timer
>might not fire in this case.
>
>Has anyone actually *ever* seen a startup problem when either:
>(a) tying MCLR straight to Vcc (Vdd), or
>(b) using a pullup resistor only (no caps, diodes, etc)?
>
>- Dan Michaels
>Oricom Technologies
>http://www.sni.net/~oricom
>
>
William K. Borsum, P.E. -- OEM Dataloggers and Instrumentation Systems
<borsum@dascor.com> & <www.dascor.com>San Diego, California, USA