Datasheet

5
2549PS–AVR–10/2012
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
CPU
GND
VCC
RESET
Po w e r
Supervision
POR / BOD &
RESET
Wat chdog
Oscillator
Wat chdog
Ti m er
Oscillator
Ci r cu i t s /
Cl o c k
Gen er at i o n
XTAL1
XTAL2
PC7..0 PORT C (8)
PA7..0
PORT A (8)
PORT D (8)
PD7..0
PORT B (8)
PB7..0
PORT E ( 8 )
PE7..0
PORT F (8)
PF7..0
PORT J (8)
PJ7..0
PG5..0 PORT G (6)
PORT H (8)
PH7..0
PORT K (8)
PK7..0
PORT L (8)
PL7..0
XRAM
TWI SPI
EEPRO M
JTAG
8 bit T/ C 0 8 bit T/ C 2
16 bit T/ C 1
16 bit T/ C 3
SRA MFLASH
16 bit T/ C 4
16 bit T/ C 5
USART 2
USART 1
USART 0
Internal
Bandgap reference
Analog
Co m p a r at o r
A/D
Co n v e r t e r
USART 3
NOTE:
Shaded par t s only available
in the 100-pin version.
Complete functionality for
t he ADC, T/ C4, an d T/ C5 o n l y
available in the 100-pin version.