I thought the 644 was rated at 20mhz? I bet it would run fine at room temp at 22.11mhz too.

I have standardized on 14.7456 MHz because that is a "magic frequency" common to both mega128 and mega644p. The boot loader and example code uses that speed although of course it is easy enough to change. I also stock some 16 MHz crystals because some of my om128 users asked for them to use with MIDI.

There is absolutely no reason why 18.432 MHz or 20 MHz shouldn't work with the om644p. If that is a strong requirement then I can provide a device with that speed crystal.

I don't subscribe to overclocking so you would be on your own with that.

Mike

I like using 20MHz and 18.432MHz (when using a UART) when it is available. I hate the idea of wasting all those Hertz, even if they are mostly used in a wait loop!

-Tony

I have updated the om644p so that you can now specify one of four clock speeds:

• 14.7456 MHz
  
• 16.0 MHz
  
• 18.432 MHz
  
• 20.0 MHz

Mike