68300

I have had a bitch of a problem with the watch crystal.  Besides the dirty 
board problem, the crystal is sensitive to heating and cooling.  It shifts 
frequency much more than a real crystal.  But then there are other problems 
to watch out for.  For example my design has the 68332 driven from the 
watch rock and a deadman timer driven from a 1MHz CTS oscillator.  The 
oscillator sometimes bursts into third overtone and runs at 2.98xx MHz.  So 
sticking in another solution may just be switching dead horses.

R. Yablonski

At 09:19 AM 5/21/03 -0500, you wrote:
> >I just want to add a little to this thread.  Apparently the customer's
> >problem was caused by solder flux left on the board.  Flux is somewhat
> >conductive, not very conductive but still, it is a conductor.
>
>I had a very similar problem--one turnkey board assembly house would send
>us boards, and we had a heck of a time with oscillator startup.  Probably
>10% failure, if not more.  I was pulling my hair out over it (as anyone on
>the list back then will remember), and of course, the assembly house would
>tell me over and over that the flux (no clean) didn't matter.  They don't
>build our boards anymore, we avoid no clean flux, and life is _much_ better.
>
> >From now on, I'll probably roll my own 4.something MHz oscillator and
>divide down to ~32 kHz (or maybe 38.4 KHz--it works out nicely for a 100 Hz
>ticker and common baud rates), rather than deal with the fragile, picky,
>slow starting 32 kHz rocks.  It's not like the '332 is micropower to begin
>with, so to me the 32kHz rock doesn't make much sense.
>
>
>newell
>
>
>
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