Datasheet
7
ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
2.4.6 Port D (PD7..0)
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.
The various special features of port D are elaborated in Section 10.3.4 “Alternate Functions of Port D” on page 69.
2.4.7 AV
CC
AV
CC
is the supply voltage pin for the A/D converter, PC3..0, and ADC7..6. It should be externally connected to V
CC
, even if
the ADC is not used. If the ADC is used, it should be connected to V
CC
through a low-pass filter. Note that PC6..4 use digital
supply voltage, V
CC
.
2.4.8 AREF
AREF is the analog reference pin for the A/D converter.
2.4.9 ADC7..6 (TQFP and QFN Package Only)
In the TQFP and QFN package, ADC7..6 serve as analog inputs to the A/D converter. These pins are powered from the
analog supply and serve as 10-bit ADC channels.