Overview
The ATmega640/1280/1281/2560/2561 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single cloc k cycle, the ATmega640/1280/1281/2560/2561 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.

Features
• High Performance, Low Power Atmel® AVR® 8-Bit Microcontroller
• Advanced RISC Architecture
   – 135 Powerful Instructions – Most Single Clock Cycle Execution
   – 32 × 8 General Purpose Working Registers
   – Fully Static Operation
   – Up to 16 MIPS Throughput at 16MHz
   – On-Chip 2-cycle Multiplier
• High Endurance Non-volatile Memory Segments
   – 64K/128K/256KBytes of In-System Self-Programmable Flash
   – 4Kbytes EEPROM
   – 8Kbytes Internal SRAM
   – Write/Erase Cycles:10,000 Flash/100,000 EEPROM
   – Data retention: 20 years at 85C/ 100 years at 25C
   – Optional Boot Code Section with Independent Lock Bits
• In-System Programming by On-chip Boot Program
• True Read-While-Write Operation
– Programming Lock for Software Security
• Endurance: Up to 64Kbytes Optional External Memory Space
• Atmel® QTouch® library support
   – Capacitive touch buttons, sliders and wheels
   – QTouch and QMatrix acquisition
   – Up to 64 sense channels
• 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 Prescaler and Compare Mode
   – Four 16-bit Timer/Counter with Separate Prescaler, Compare- and Capture Mode
   – Real Time Counter with Separate Oscillator
   – Four 8-bit PWM Channels
   – Six/Twelve PWM Channels with Programmable Resolution from 2 to 16 Bits (ATmega1281/2561, ATmega640/1280/2560)
   – Output Compare Modulator
   – 8/16-channel, 10-bit ADC (ATmega1281/2561, ATmega640/1280/2560)
   – Two/Four Programmable Serial USART (ATmega1281/2561, ATmega640/1280/2560)
   – Master/Slave SPI Serial Interface
   – Byte Oriented 2-wire Serial Interface
   – Programmable Watchdog Timer with Separate On-chip Oscillator
   – On-chip Analog Comparator
   – Interrupt and Wake-up on Pin Change
• Special Microcontroller Features
   – Power-on Reset and Programmable Brown-out Detection
   – Internal Calibrated Oscillator
   – External and Internal Interrupt Sources
   – Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby
• I/O and Packages
   – 54/86 Programmable I/O Lines (ATmega1281/2561, ATmega640/1280/2560)
   – 64-pad QFN/MLF, 64-lead TQFP (ATmega1281/2561)
   – 100-lead TQFP, 100-ball CBGA (ATmega640/1280/2560)
   – RoHS/Fully Green
• Temperature Range:
   – -40°C to 85°C Industrial
• Ultra-Low Power Consumption
   – Active Mode: 1MHz, 1.8V: 500µA
   – Power-down Mode: 0.1µA at 1.8V
• Speed Grade:
   – ATmega640V/ATmega1280V/ATmega1281V:
      • 0 - 4MHz @ 1.8V - 5.5V, 0 - 8MHz @ 2.7V - 5.5V
   – ATmega2560V/ATmega2561V:
      • 0 - 2MHz @ 1.8V - 5.5V, 0 - 8MHz @ 2.7V - 5.5V
   – ATmega640/ATmega1280/ATmega1281:
      • 0 - 8MHz @ 2.7V - 5.5V, 0 - 16MHz @ 4.5V - 5.5V
   – ATmega2560/ATmega2561:
      • 0 - 16MHz @ 4.5V - 5.5V