New Atmel ATmega128RFA1 Wireless AVR® Microcontroller

http://www.atmel.com/dyn/resources/prod_documents/doc8266.pdf

The basic AVR feature set of the ATmega128RFA1 is derived from the ATmega1281/2561. Address locations and names of the implemented modules and registers are unchanged as long as it fits the target application of a very small and power efficient radio system. In addition, several new features were added. Backward compatibility of the ATmega128RFA1 to the ATmega1281/2561 is provided in most cases. However some incompatibilities between the microcontrollers exist.