ATMEGA644RFR2 PDF File ( Datasheet )

ATmega2564, 1284, 644RFR2 Features Network support by hardware assisted Multiple PAN Address Filtering Advanced Hardware assisted Reduced Power Consumption High Performance, Low Power AVR® 8-Bit Microcontroller Advanced RISC Architecture - 135 Powerful Instructions Most Single Clock Cycle Execution - 32x8 General Purpose Working Registers , On-Chip 2-cycle Multiplier - Up to 16 MIPS Throughput at 16 MH- and 1.8V Fully Static Operation Non-volatile Program and Data Memories - 256K, 128K