iam presently working on ATmega controller, but now i need to change over to ATXmega controller,as my project needs more serial ports. I need your help for solving the following queries: 1) what is the difference between the two in terms of hardware and software? 2)can same c program written for ATmega be used for ATXmega , if not then what would be modifications? 3)does any of the ATmega controller support 3 UARTS or more?