Hi Brian,
Everyone else answered your question for me! As they said, NTSC
colorburst crystals are very common and very cheap. The firmware in
the micro doesn't need a higher clock frequency than that, so that's
why I chose it.
The micro internally divides the 3.58MHz by 8950 (179 x 50) to
produce a 400Hz reference for all its timing. It worked out pretty
well.

Regards,
Bob



"Brian Goldsmith" wrote:


"Michael A. Terrell" wrote


Bob Parker wrote:

The DSE ESR meter uses 3.58MHz....

Bob


Was that because you had plenty on hand, or was it recommended for
the microprocessor you selected?



**** As 3.579545 MHz is the NTSC colour burst frequency,there are millions
of these crystals around the world.Because of availibility and low cost,they
get used in all sorts of circuits.

Brian Goldsmith.