64
2588F–AVR–06/2013
ATtiny261/461/861
Port A, Bit 5 – ADC4/AIN2/PCINT5
ADC4: Analog to Digital Converter, Channel 4.
AIN2: Analog Comparator Input. Configure the port pin as input with the internal pull-up
switched off to avoid the digital port function from interfering with the function of the Analog
Comparator.
PCINT5: Pin Change Interrupt source 5.
Port A, Bit 4 – ADC3/ICP0/PCINT4
ADC3: Analog to Digital Converter, Channel 3.
ICP0: Timer/Counter0 Input Capture Pin.
PCINT4: Pin Change Interrupt source 4.
Port A, Bit 3 – AREF/PCINT3
AREF: External analog reference for ADC. Pullup and output driver are disabled on PA3
when the pin is used as an external reference or internal voltage reference with external
capacitor at the AREF pin.
PCINT3: Pin Change Interrupt source 3.
Port A, Bit 2 – ADC2/INT1/USCK/SCL/PCINT2
ADC2: Analog to Digital Converter, Channel 2.
INT1: The PA2 pin can serve as an External Interrupt source 1.
USCK: Three-wire mode Universal Serial Interface Clock.
SCL: Two-wire mode Serial Clock for USI Two-wire mode.
PCINT2: Pin Change Interrupt source 2.
Port A, Bit 1 – ADC1/DO/PCINT1
ADC1: Analog to Digital Converter, Channel 1.
DO: Three-wire mode Universal Serial Interface Data output. Three-wire mode Data output
overrides PORTA1 value and it is driven to the port when data direction bit DDA1 is set.
PORTA1 still enables the pull-up, if the direction is input and PORTA1 is set.
PCINT1: Pin Change Interrupt source 1.
Port A, Bit 0 – ADC0/DI/SDA/PCINT0
ADC0: Analog to Digital Converter, Channel 0.
DI: Data Input in USI Three-wire mode. USI Three-wire mode does not override normal port
functions, so pin must be configure as an input for DI function.
SDA: Two-wire mode Serial Interface Data.
PCINT0: Pin Change Interrupt source 0.