2.2
Comparison Between ATmega1281/2561 and ATmega640/1280/2560
Each device in the ATmega640/1280/1281/2560/2561 family differs only in memory size and number of pins. Table
2-1 summarizes the different configurations for the six devices.
Table 2-1.
Configuration Summary
General
Purpose I/O pins
16 bits resolution
PWM channels
Serial
USARTs
ADC
Channels
Device
Flash
64KB
EEPROM
4KB
RAM
8KB
8KB
8KB
8KB
8KB
ATmega640
ATmega1280
ATmega1281
ATmega2560
ATmega2561
86
86
54
86
54
12
12
6
4
4
2
4
2
16
16
8
128KB
128KB
256KB
256KB
4KB
4KB
4KB
12
6
16
8
4KB
2.3
Pin Descriptions
2.3.1
VCC
Digital supply voltage.
2.3.2
2.3.3
GND
Ground.
Port A (PA7..PA0)
Port A is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port A output buf-
fers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port A pins that are
externally pulled low will source current if the pull-up resistors are activated. The Port A pins are tri-stated when a
reset condition becomes active, even if the clock is not running.
Port A also serves the functions of various special features of the ATmega640/1280/1281/2560/2561 as listed on
page 75.
2.3.4
Port B (PB7..PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buf-
fers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are
externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a
reset condition becomes active, even if the clock is not running.
Port B has better driving capabilities than the other ports.
Port B also serves the functions of various special features of the ATmega640/1280/1281/2560/2561 as listed on
page 76.
2.3.5
Port C (PC7..PC0)
Port C is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port C output buf-
fers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are
externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a
reset condition becomes active, even if the clock is not running.
Port C also serves the functions of special features of the ATmega640/1280/1281/2560/2561 as listed on page 79.
ATmega640/V-1280/V-1281/V-2560/V-2561/V [SUMMARY]
7
2549QS–AVR–02/2014
ATMEL [ ATMEL ]
