Datasheet

6
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P [SUMMARY]
8285ES–AVR–02/2013
2.2 Comparison between Atmel
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P
2.3 Pin descriptions
2.3.1 VCC
Digital supply voltage.
2.3.2 GND
Ground.
2.3.3 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
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P as listed on ”Alternate functions of
Port B” on page 68.
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
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P as listed on ”Alternate functions of
Port B” on page 68.
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
Table 2-1. Differences between: ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/6450A/6450P.
Device Flash EEPROM RAM MHz
ATmega165A 16Kbyte 512Bytes 1Kbyte 16
ATmega165PA 16Kbyte 512Bytes 1Kbyte 16
ATmega325A 32Kbyte 1Kbyte 2Kbyte 20
ATmega325PA 32Kbyte 1Kbyte 2Kbyte 20
ATmega3250A 32Kbytes 1Kbyte 2Kbyte 20
ATmega3250PA 32Kbyte 1Kbyte 2Kbyte 20
ATmega645A 64Kbyte 2Kbyte 4Kbyte 16
ATmega645P 64Kbyte 2Kbyte 4Kbyte 16
ATmega6450A 64Kbyte 2Kbyte 4Kbyte 20
ATmega6450P 64Kbyte 2Kbyte 4Kbyte 20