61
8006K–AVR–10/10
ATtiny24/44/84
10.2.1
Alternate Functions of Port A
The Port A pins with alternate function are shown in
Table 10-3. Port A, Bit 0 – ADC0/AREF/PCINT0
ADC0: Analog to Digital Converter, Channel 0.
AREF: External Analog Reference for ADC. Pullup and output driver are disabled on PA0
when the pin is used as an external reference or Internal Voltage Reference with external
capacitor at the AREF pin by setting (one) the bit REFS0 in the ADC Multiplexer Selection
Register (ADMUX).
PCINT0: Pin Change Interrupt source 0. The PA0 pin can serve as an external interrupt
source for pin change interrupt 0.
Table 10-3.
Port A Pins Alternate Functions
Port Pin
Alternate Function
PA0
ADC0:
ADC Input Channel 0
AREF:
External Analog Reference
PCINT0: Pin Change Interrupt 0, Source 0
PA1
ADC1:
ADC Input Channel 1
AIN0:
Analog Comparator, Positive Input
PCINT1:Pin Change Interrupt 0, Source 1
PA2
ADC2:
ADC Input Channel 2
AIN1:
Analog Comparator, Negative Input
PCINT2: Pin Change Interrupt 0, Source 2
PA3
ADC3:
ADC Input Channel 3
T0:
Timer/Counter0 Clock Source.
PCINT3: Pin Change Interrupt 0, Source 3
PA4
ADC4:
ADC Input Channel 4
USCK:
USI Clock (Three Wire Mode)
SCL :
USI Clock (Two Wire Mode)
T1:
Timer/Counter1 Clock Source
PCINT4: Pin Change Interrupt 0, Source 4
PA5
ADC5:
ADC Input Channel 5
DO:
USI Data Output (Three Wire Mode)
MISO:
SPI Master Data Input / Slave Data Output
OC1B:
Timer/Counter1 Compare Match B Output
PCINT5: Pin Change Interrupt 0, Source 5
PA6
ADC6:
ADC Input Channel 6
DI:
USI Data Input (Three Wire Mode)
SDA:
USI Data Input (Two Wire Mode)
MOSI:
SPI Master Data Output / Slave Data Input
OC1A:
Timer/Counter1 Compare Match A Output
PCINT6: Pin Change Interrupt 0, Source 6
PA7
ADC7:
ADC Input Channel 7
OC0B:
Timer/Counter0 Compare Match B Output
ICP1:
Timer/Counter1 Input Capture Pin
PCINT7: Pin Change Interrupt 0, Source 7