Xtal value? (Q1)

[spumanti]

Hi !

A question about Q1.

In the diagram it is a 14,7456 MHz Xtal used to clock the ATMega8.

Can I use any Xtal, or does it have to be the 14,7456 MHz one? (I can't get an Xtal with that specific frequency).
Can I use any of the following ones: 12,288 MHz, 15,000 MHz, 16,000 MHz  ??? (these are Xtals that I have available)

Thanks in advance.  

[Vitat]

Maybe 15MHz will be work, but not perfectly.

[spumanti]

ok...

Is it a timing problem, or...  

Can I change something in the software (in the ATMega8) to make it work better, or maybe use the internal clock in the ATMega8?

[Vitat]

1. You must change Xtal in Constant.h for normal use Uart speed.
2. If emulator will be not work fine with Head Unit, you must adapt timings in link.c.

[spumanti]

ok... sounds a bit complicated, since i dont know anything about the timings of the signals and so on... but i'll have to try, since i can't get the right Xtal

Thanks for the info