ATTINY87 datasheet(5/292 Pages) ATMEL

5 / 292 page

8265A–AVR–08/10

ATtiny87/ATtiny167

1.5

Pin Description

1.5.1

VCC

Supply voltage.

1.5.2

GND

Ground.

1.5.3

AVCC

Analog supply voltage.

1.5.4

AGND

Analog ground.

1.5.5

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 A also serves the functions of various special features of the ATtiny87/167 as listed on

Section 9.3.3 “Alternate Functions of Port A” on page 76.

1.5.6

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 also serves the functions of various special features of the ATtiny87/167 as listed on

Section 9.3.4 “Alternate Functions of Port B” on page 81.

ATTINY87 Datasheet(PDF) 5 Page - ATMEL Corporation