On Fri, 22 Feb 2002 19:45:00 -0800, Thomas wrote:

>Hello everyone,
>
>I am building the ICD.  I am wondering if I can replace the 3.6864Mhz
>crystal by 4.0Mhz or 3.5Mhz crystal.  The reason is that I have lots of
>these crystals.
>

At a minimum, you'd need to find and modify the value that's being put
into the baud bate generator register.=20

If software delays are used (and I'd expect that they are), the ICD
code may 1) still work at the different frequency, 2) work marginally,
or 3) fail miserably. Unless someone has disassembled and analyzed
mpl876.hex, it would be sheer guesswork to speculate on this issue.

Like you, I'm always looking to use my own 'junk box' parts but
crystals for other people's designs don't usually fall into this
category. The 3.6864 MHz frequency is a standard crystal available
through Digikey, Mouser and undoubtedly dozens of other sources. I'd
suggest you just spring for the new rock and be done with it.

Regards, Bob

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