ATmega48PA/88PA/168PA/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.
Table 13-10 and Table 13-11 relate the alternate functions of Port D to the overriding signals
shown in Figure 13-5 on page 80.
Table 13-10. 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
PUO
0
0
0
0
0
0
0
0
DDOE
DDOV
PVOE
PVOV
DIEOE
DIEOV
0
0
0
0
0
0
0
0
0
OC0A ENABLE
OC0B ENABLE
UMSEL
0
OC0A
OC0B
XCK OUTPUT
PCINT20 • PCIE2
1
PCINT23 • PCIE2
1
PCINT22 • PCIE2
1
PCINT21 • PCIE2
1
PCINT20 INPUT
XCK INPUT
T0 INPUT
PCINT21 INPUT
T1 INPUT
DI
PCINT23 INPUT
AIN1 INPUT
PCINT22 INPUT
AIN0 INPUT
AIO
–
–
90
8161D–AVR–10/09
ATMEL [ ATMEL ]
