Comparison between
ATmega329,
ATmega3290,
ATmega649 and
ATmega6490
The ATmega329, ATmega3290, ATmega649, and ATmega6490 differs only in memory
sizes, pin count and pinout. Table 1 on page 6 summarizes the different configurations
for the four devices.
Table 1.
Configuration Summary
Device
ATmega329
ATmega3290
ATmega649
ATmega6490
Flash
32K bytes
32K bytes
64K bytes
64K bytes
EEPROM
1K bytes
1K bytes
2K bytes
2K bytes
RAM
2K bytes
2K bytes
4K bytes
4K bytes
LCD
Segments
4 x 25
4 x 40
4 x 25
4 x 40
General Purpose
I/O Pins
54
69
54
69
Pin Descriptions
V
CC
GND
Port A (PA7..PA0)
The following section describes the I/O-pin special functions.
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
ATmega329/3290/649/6490 as listed on page 67.
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
ATmega329/3290/649/6490 as listed on page 68.
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 features of the ATmega329/3290/649/6490
as listed on page 71.
Port D (PD7..PD0)
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
current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
6
ATmega329/3290/649/6490
2552HS–AVR–11/06
ATMEL [ ATMEL CORPORATION ]
