Datasheet

Port Pin Alternate Functions
PB3 AIN1 (Analog Comparator Negative Input)
OC0 (Timer/Counter0 Output Compare Match Output)
PB2 AIN0 (Analog Comparator Positive Input)
INT2 (External Interrupt 2 Input)
PB1 T1 (Timer/Counter1 External Counter Input)
PB0 T0 (Timer/Counter0 External Counter Input)
XCK (USART External Clock Input/Output)
The alternate pin configuration is as follows:
• SCK – Port B, Bit 7
SCK: Master Clock output, Slave Clock input pin for SPI. When the SPI is enabled as a Slave, this pin is
configured as an input regardless of the setting of DDB7. When the SPI is enabled as a Master, the data
direction of this pin is controlled by DDB7. When the pin is forced by the SPI to be an input, the pull-up
can still be controlled by the PORTB7 bit.
• MISO – Port B, Bit 6
MISO: Master Data input, Slave Data output pin for SPI. When the SPI is enabled as a Master, this pin is
configured as an input regardless of the setting of DDB6. When the SPI is enabled as a Slave, the data
direction of this pin is controlled by DDB6. When the pin is forced by the SPI to be an input, the pull-up
can still be controlled by the PORTB6 bit.
• MOSI – Port B, Bit 5
MOSI: SPI Master Data output, Slave Data input for SPI. When the SPI is enabled as a Slave, this pin is
configured as an input regardless of the setting of DDB5. When the SPI is enabled as a Master, the data
direction of this pin is controlled by DDB5. When the pin is forced by the SPI to be an input, the pull-up
can still be controlled by the PORTB5 bit.
• SS – Port B, Bit 4
SS: Slave Select input. When the SPI is enabled as a Slave, this pin is configured as an input regardless
of the setting of DDB4. As a Slave, the SPI is activated when this pin is driven low. When the SPI is
enabled as a Master, the data direction of this pin is controlled by DDB4. When the pin is forced by the
SPI to be an input, the pull-up can still be controlled by the PORTB4 bit.
• AIN1/OC0 – Port B, Bit 3
AIN1, Analog Comparator Negative 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.
OC0, Output Compare Match output: The PB3 pin can serve as an external output for the Timer/Counter0
Compare Match. The PB3 pin has to be configured as an output (DDB3 set (one)) to serve this function.
The OC0 pin is also the output pin for the PWM mode timer function.
• AIN0/INT2 – Port B, Bit 2
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.
INT2, External Interrupt Source 2: The PB2 pin can serve as an external interrupt source to the MCU.
• T1 – Port B, Bit 1
Atmel ATmega32A [DATASHEET]
Atmel-8155I-ATmega32A_Datasheet_Complete-08/2016
82