Atmel Corporation ATMEGA644-20AUR Connectivity: I??C, SPI, UART/USART Core Processor: AVR Core Size: 8-Bit Data Converters: A/D 8x10b Eeprom Size: 2K x 8 Number Of I /o: 32 Operating Temperature: -40?°C ~ 85?°C Oscillator Type: Internal Package / Case: * Peripherals: Brown-out Detect/Reset, POR, PWM, WDT Program Memory Size: 64KB (32K x 16) Program Memory Type: FLASH Ram Size: 4K x 8 Series: AVR?® ATmega Speed: 20MHz Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V