ATmega640/1280/1281/2560/2561
2. 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 clock 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.
2.1
Block Diagram
Figure 2-1. Block Diagram
PF7..0
PK7..0
PJ7..0
PE7..0
VCC
Power
Supervision
POR / BOD &
RESET
PORT F (8)
PORT K (8)
PORT J (8)
PORT E (8)
RESET
Watchdog
Timer
GND
Analog
Comparator
A/D
Converter
Watchdog
Oscillator
JTAG
USART 0
USART 3
USART 1
USART 2
XTAL1
Oscillator
Circuits /
Clock
Internal
Bandgap reference
16bit T/C 3
EEPROM
Generation
16bit T/C 5
16bit T/C 4
16bit T/C 1
XTAL2
CPU
PORT A (8)
PORT G (6)
PA7..0
PG5..0
FLASH
SRAM
XRAM
TWI
SPI
8bit T/C 0
8bit T/C 2
PC7..0
PORT C (8)
NOTE:
Shaded parts only available
in the 100-pin version.
Complete functionality for
the ADC, T/C4, and T/C5 only
available in the 100-pin version.
PORT D (8)
PORT B (8)
PORT H (8)
PORT L (8)
PD7..0
PB7..0
PH7..0
PL7..0
5
2549LS–AVR–08/07
ATMEL [ ATMEL ]
