Mike Keitz wrote:
> The official method is to use an external clock source connected to the
> OSC1 pins of all the PICs.  The PICs should be set to LP, XT, or HS mode
> depending on the clock rate.  The external clock must meet the input high
> and low voltage specifications for the OSC1 pin.  Many of the canned
> "TTL" oscillators don't.  If using an oscillator can (which I think is
> much better than trying to build a gate oscillator), be sure it is rated
> for CMOS level output.

If power is an issue, you can set the configuration fuses for LP no
matter what the frequency.  All the fuses are doing is establishing the
amount of feedback to drive the crystal.  An external oscillator doesn't
require this feedback.  Most oscillators probably have enough drive for
a handful of PICs so, for reliability, don't use OSC2 as an output.

--Matt