5

ATmega165/V

2573FS–AVR–08/06

Pin Descriptions

VCC

Digital supply voltage.

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 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 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 ATmega165 as listed

on page 62.

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 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.

Port D also serves the functions of various special features of the ATmega165 as listed

on page 65.

Port E (PE7..PE0)

Port E is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each

bit). The Port E output buffers have symmetrical drive characteristics with both high sink

and source capability. As inputs, Port E pins that are externally pulled low will source

current if the pull-up resistors are activated. The Port E pins are tri-stated when a reset

condition becomes active, even if the clock is not running.

Port E also serves the functions of various special features of the ATmega165 as listed

on page 66.

Port F (PF7..PF0)

Port F serves as the analog inputs to the A/D Converter.

Port F also serves as an 8-bit bi-directional I/O port, if the A/D Converter is not used.

Port pins can provide internal pull-up resistors (selected for each bit). The Port F output

buffers have symmetrical drive characteristics with both high sink and source capability.

As inputs, Port F pins that are externally pulled low will source current if the pull-up

resistors are activated. The Port F pins are tri-stated when a reset condition becomes

active, even if the clock is not running. If the JTAG interface is enabled, the pull-up resis-