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7598H–AVR–07/09
ATtiny25/45/85
OC0B: Output Compare Match output. The PB1 pin can serve as an external output for the
Timer/Counter0 Compare Match B. The PB1 pin has to be configured as an output (DDB1 set
(one)) to serve this function. The OC0B pin is also the output pin for the PWM mode timer
function.
OC1A: Output Compare Match output: The PB1 pin can serve as an external output for the
Timer/Counter1 Compare Match B when configured as an output (DDB1 set). The OC1A pin is
also the output pin for the PWM mode timer function.
DO: Three-wire mode Universal Serial Interface Data output. Three-wire mode Data output over-
rides PORTB1 value and it is driven to the port when data direction bit DDB1 is set (one).
PORTB1 still enables the pull-up, if the direction is input and PORTB1 is set (one).
PCINT1: Pin Change Interrupt source 1.
• Port B, Bit 0 - MOSI/AIN0/OC0A/OC1A/DI/SDA/AREF/PCINT0
MOSI: SPI Master Data output, Slave Data input for SPI channel. When the SPI is enabled as a
Slave, this pin is configured as an input regardless of the setting of DDB0. When the SPI is
enabled as a Master, the data direction of this pin is controlled by DDB0. When the pin is forced
by the SPI to be an input, the pull-up can still be controlled by the PORTB0 bit.
AIN0: Analog Comparator Positive 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.
OC0A: Output Compare Match output. The PB0 pin can serve as an external output for the
Timer/Counter0 Compare Match A when configured as an output (DDB0 set (one)). The OC0A
pin is also the output pin for the PWM mode timer function.
OC1A: Inverted Output Compare Match output: The PB0 pin can serve as an external output for
the Timer/Counter1 Compare Match B when configured as an output (DDB0 set). The OC1A pin
is also the inverted output pin for the PWM mode timer function.
SDA: Two-wire mode Serial Interface Data.
AREF: External Analog Reference for ADC. Pullup and output driver are disabled on PB0 when
the pin is used as an external reference or Internal Voltage Reference with external capacitor at
the AREF pin.
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.
PCINT0: Pin Change Interrupt source 0.