ATMEGA644-20PU Datasheet PDF - ATMEL

The ATMEGA644-20PU is a 8-bit high-performance low-power AVR RISC-based Microcontroller combines 64kB ISP flash memory with read-while-write capabilities, 2kB EEPROM, 4kB SRAM, 32 general purpose I/O lines, 32 general purpose working registers, real time counter, three flexible timer/counters with compare modes and PWM, 2 USARTs, byte oriented 2-wire serial interface, 8-channel/10-bit A/D converter with optional differential input stage with programmable gain, programmable watchdog timer with internal oscillator, SPI serial port, JTAG (IEEE 1149.1 compliant) test interface for on-chip debugging and six software selectable power saving modes. The device operates between 2.7 to 5.5V. By executing powerful instructions in a single clock-cycle, the device achieves throughputs approaching 1 MIPS per MHz, balancing power consumption and processing speed.

● Advanced RISC architecture - Fully static operation

● High endurance, non-volatile memory segments

● JTAG (IEEE 1149.1 compliant) interface

● Peripheral features - Real time counter with separate oscillator

● Power-on reset (POR) and programmable brown-out detection

● Internal calibrated RC oscillator

● External and internal interrupt sources

● Six sleep modes - Idle, ADC noise reduction, power-save, power-down, standby and extended standby