3

8008HS–AVR–04/11

ATtiny48/88

1.1

Pin Descriptions

1.1.1

VCC

Digital supply voltage.

1.1.2

AVCC

AV

be externally connected to V

mended this pin is connected to V

The following pins receive their supply voltage from AV

ages) PA[1:0]. All other I/O pins take their supply voltage from V

1.1.3

GND

Ground.

1.1.4

Port A (PA3:0)

Port A is a 4-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The

PA[3:0] output buffers have symmetrical drive characteristics with both sink and source capabil-

ity. 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.

This port is available in 32-lead TQFP, 32-pad QFN and 32-ball UFBGA packages, only.

1.1.5

Port B (PB7:0)

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 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.

Depending on the clock selection fuse settings, PB6 can be used as input to the internal clock

operating circuit.

1.1.6

Port C (PC7, PC5:0)

Port C is a 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The

PC7 and PC[5:0] output buffers have symmetrical drive characteristics with both 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.

1.1.7

PC6/RESET

If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical char-

acteristics of PC6 differ from those of the other pins of Port C.

If the RSTDISBL Fuse is unprogrammed, PC6 is used as a reset input. A low level on this pin for

longer than the minimum pulse width will generate a reset, even if the clock is not running. The