90
8025I–AVR–02/09
ATmega48P/88P/168P/328P
• INT0/PCINT18 – Port D, Bit 2
INT0, External Interrupt source 0: The PD2 pin can serve as an external interrupt source.
PCINT18: Pin Change Interrupt source 18. The PD2 pin can serve as an external interrupt
source.
• TXD/PCINT17 – Port D, Bit 1
TXD, Transmit Data (Data output pin for the USART). When the USART Transmitter is enabled,
this pin is configured as an output regardless of the value of DDD1.
PCINT17: Pin Change Interrupt source 17. The PD1 pin can serve as an external interrupt
source.
• RXD/PCINT16 – Port D, Bit 0
RXD, Receive Data (Data input pin for the USART). When the USART Receiver is enabled this
pin is configured as an input regardless of the value of DDD0. When the USART forces this pin
to be an input, the pull-up can still be controlled by the PORTD0 bit.
PCINT16: Pin Change Interrupt source 16. The PD0 pin can serve as an external interrupt
source.
and
relate the alternate functions of Port D to the overriding signals
shown in
Table 11-10. Overriding Signals for Alternate Functions PD7..PD4
Signal
Name
PD7/AIN1
/PCINT23
PD6/AIN0/
OC0A/PCINT22
PD5/T1/OC0B/
PCINT21
PD4/XCK/
T0/PCINT20
PUOE
0
0
0
0
PUO
0
0
0
0
DDOE
0
0
0
0
DDOV
0
0
0
0
PVOE
0
OC0A ENABLE
OC0B ENABLE
UMSEL
PVOV
0
OC0A
OC0B
XCK OUTPUT
DIEOE
PCINT23 • PCIE2
PCINT22 • PCIE2
PCINT21 • PCIE2
PCINT20 • PCIE2
DIEOV
1
1
1
1
DI
PCINT23 INPUT
PCINT22 INPUT
PCINT21 INPUT
T1 INPUT
PCINT20 INPUT
XCK INPUT
T0 INPUT
AIO
AIN1 INPUT
AIN0 INPUT
–
–