5

8006FS–AVR–02/07

ATtiny24/44/84

2.2

Pin Descriptions

2.2.1

VCC

Supply voltage.

2.2.2

GND

Ground.

2.2.3

Port B (PB3...PB0)

Port B is a 4-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 except PB3 which has the RESET capability. To use pin PB3 as an I/O pin, instead of

RESET pin, program (‘0’) RSTDISBL fuse. 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 ATtiny24/44/84 as listed on

2.2.4

RESET

Reset input. A low level on this pin for longer than the minimum pulse length will generate a

2.2.5

Port A (PA7...PA0)

Port A is a 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 has an alternate functions as analog inputs for the ADC, analog comparator,

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3.

Resources

A comprehensive set of development tools, drivers and application notes, and datasheets are

available for download on http://www.atmel.com/avr.