Datasheet

– PCINT30: Pin Change Interrupt source 30. The PD6 pin can serve as an external interrupt
source.
• OC1A/PCINT29 – Port D, Bit 5
– OC1A: Output Compare Match output. The PD5 pin can serve as an external output for the
Timer/Counter1 Compare Match A. The PD5 pin has to be configured as an output (DDD5 set
'1') to serve this function. The OC1A pin is also the output pin for the PWM mode timer
function.
– PCINT29: Pin Change Interrupt source 29. The PD5 pin can serve as an external interrupt
source.
• OC1B/XCK1/PCINT28 – Port D, Bit 4
– OC1B: Output Compare Match B output. The PD4 pin can serve as an external output for the
Timer/Counter1 Output Compare B. The pin has to be configured as an output (DDD4 set '1')
to serve this function. The OC1B pin is also the output pin for the PWM mode timer function.
– XCK1: USART1 external clock.
– PCINT28: Pin Change Interrupt source 28. The PD4 pin can serve as an external interrupt
source.
• INT1/TXD1/PCINT27 – Port D, Bit 3
– INT1: External Interrupt source 1. The PD3 pin can serve as an external interrupt source.
– TXD1: 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 DDD3.
– PCINT27: Pin Change Interrupt source 27. The PD3 pin can serve as an external interrupt
source.
• INT0/RXD1/PCINT26 – Port D, Bit 2
– INT0: External Interrupt source 0. The PD2 pin can serve as an external interrupt source.
– RXD1: Receive Data (Data input pin for the USART1). When the USART1 Receiver is
enabled this pin is configured as an input regardless of the value of DDD2. When the USART
forces this pin to be an input, the pull-up can still be controlled by the PORTD2 bit.
– PCINT26: Pin Change Interrupt source 26. The PD2 pin can serve as an external interrupt
source.
• TXD0/PCINT25 – Port D, Bit 1
– TXD0: Transmit Data (Data output pin for the USART0). When the USART0 Transmitter is
enabled, this pin is configured as an output regardless of the value of DDD1.
– PCINT25: Pin Change Interrupt source 25. The PD1 pin can serve as an external interrupt
source.
• RXD0/PCINT24 – Port D, Bit 0
– RXD0: Receive Data (Data input pin for the USART0). When the USART0 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.
– PCINT24: Pin Change Interrupt source 24. The PD0 pin can serve as an external interrupt
source.
The tables below relate the alternate functions of Port D to the overriding signals shown in Figure 15-5.
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
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