ATmega640/1280/1281/2560/2561
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 summarizes the different configurations for the six devices.
Table 2.
Configuration Summary
Device
ATmega640
ATmega1280
ATmega1281
ATmega2560
ATmega2561
Flash
64KB
128KB
128KB
256KB
256KB
EEPROM
4KB
4KB
4KB
4KB
4KB
RAM
8KB
8KB
8KB
8KB
8KB
General
Purpose I/O pins
86
86
54
86
54
16 bits resolution
PWM channels
12
12
6
12
6
Serial
USARTs
4
4
2
4
2
ADC
Channels
16
16
8
16
8
Pin Descriptions
VCC
GND
Port A (PA7..PA0)
Digital supply voltage.
Ground.
Port A is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port A output buffers 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 91.
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 buffers 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 92.
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 buffers 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
ATmega640/1280/1281/2560/2561 as listed on page 95.
Port D (PD7..PD0)
features
of
the
Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port D output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port D pins that are externally pulled low will source
7
2549K–AVR–01/07
ATMEL [ ATMEL CORPORATION ]
