Datasheet

Port Pin Alternate Function
PC3 TMS (JTAG Test Mode Select)
PCINT19 (Pin Change Interrupt 19)
PC2 TCK (JTAG Test Clock)
PCINT18 (Pin Change Interrupt 18)
PC1 SDA (two-wire Serial Bus Data Input/Output Line)
PCINT17 (Pin Change Interrupt 17)
PC0 SCL (two-wire Serial Bus Clock Line)
PCINT16 (Pin Change Interrupt 16)
The alternate pin configuration is as follows:
• TOSC2/PCINT23 – Port C, Bit 7
– TOSC2: Timer Oscillator pin 2. The PC7 pin can serve as an external interrupt source to the
MCU.
– PCINT23: Pin Change Interrupt source 23. The PC7 pin can serve as an external interrupt
source.
• TOSC1/PCINT22 – Port C, Bit 6
– TOSC1: Timer Oscillator pin 1. The PC6 pin can serve as an external interrupt source to the
MCU.
– PCINT22: Pin Change Interrupt source 22. The PC6 pin can serve as an external interrupt
source.
• TDI/PCINT21 – Port C, Bit 5
– TDI: JTAG Test Data Input.
– PCINT21: Pin Change Interrupt source 21. The PC5 pin can serve as an external interrupt
source.
• TDO/PCINT20 – Port C, Bit 4
– TDO: JTAG Test Data Output.
– PCINT20: Pin Change Interrupt source 20. The PC4 pin can serve as an external interrupt
source.
• TMS/PCINT19 – Port C, Bit 3
– TMS: JTAG Test Mode Select.
– PCINT19: Pin Change Interrupt source 19. The PC3 pin can serve as an external interrupt
source.
• TCK/PCINT18 – Port C, Bit 2
– TCK: JTAG Test Clock.
– PCINT18: Pin Change Interrupt source 18. The PC2 pin can serve as an external interrupt
source.
• SDA/PCINT17 – Port C, Bit 1
– SDA: two-wire Serial Bus Data Input/Output Line
– PCINT17: Pin Change Interrupt source 17. The PC1 pin can serve as an external interrupt
source.
Atmel ATmega644A [DATASHEET]
Atmel-42716C-ATmega644A_Datasheet_Complete-10/2016
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