4-Bit/8-Bit MCU

The ATmega644 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega644 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.

• High-performance, Low-power AVR® 8-bit Microcontroller
• Advanced RISC Architecture
  • 131 Powerful Instructions - Most Single-clock Cycle Execution
  • 32 × 8 General Purpose Working Registers
  • Fully Static Operation
  • Up to 20 MIPS Throughput at 20MHz
• High Endurance non--volatile Memory segments
  • 64 Kbytes of In-System Self-programmable Flash program memory
  • 2 Kbytes EEPROM
  • 4 Kbytes Internal SRAM
  • Write/Erase cyles: 10,000 Flash/100,000 EEPROM
  • Data retention: 20 years at 85°C/100 years at 25°C
• JTAG (IEEE std. 1149.1 Compliant) Interface
  • Boundary-scan Capabilities According to the JTAG Standard
  • Extensive On-chip Debug Support
  • Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface
• Peripheral Features
  • Two 8-bit Timer/Counters with Separate Prescalers and Compare Modes
  • One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode
  • Real Time Counter with Separate Oscillator
  • Six PWM Channels
  • 8-channel, 10-bit ADC Differential mode with selectable gain at 1x, 10x or 200x
  • Byte-oriented Two-wire Serial Interface
  • One Programmable Serial USART
  • Master/Slave SPI Serial Interface
  • Programmable Watchdog Timer with Separate On-chip Oscillator
  • On-chip Analog Comparator
  • Interrupt and Wake-up on Pin Change