Datasheet Atmel ATmega644-20PU

Features
• High-performance, Low-power Atmel® 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(1)(3)
- Data retention: 20 years at 85°C/100 years at 25°C(2)(3)
- 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
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 …