Also, if you want to use the clock source (system clock - which I believe is any of the clock sources, based on my reading of the datasheet) to drive another device, you get that from the CLKO pin (PB0, pin 14 on the 28 pin PDIP).
Yea so specifically what parts would they be able to share? I know for sure they cannot share the 16MHz Crystal.
Why do i not need to use the clock Crystal? I thought the ATmega chip needed that. Can you please Elaborate?