Datasheet

– PCINT4: Pin Change Interrupt source 4. The PB4 pin can serve as an external interrupt
source.
• MOSI0/TXD1/OC2A/PCINT3 – Port B, Bit 3
– MOSI0: SPI0 Master Data output, Slave Data input for SPI0 channel. When the SPI0 is
enabled as a Slave, this pin is configured as an input regardless of the setting of DDB3. When
the SPI0 is enabled as a Master, the data direction of this pin is controlled by DDB3. When
the pin is forced by the SPI0 to be an input, the pull-up can still be controlled by the PORTB3
bit.
– TXD1: Transmit Data (Data output pin for the USART1). When the USART1 Transmitter is
enabled, this pin is configured as an output regardless of the value of DDB3.
– OC2A: Output Compare Match output. The PB3 pin can serve as an external output for the
Timer/Counter2 Compare Match A. The PB3 pin has to be configured as an output (DDB3 set
'1') to serve this function. The OC2A pin is also the output pin for the PWM mode timer
function.
– PCINT3: Pin Change Interrupt source 3. The PB3 pin can serve as an external interrupt
source.
• SS0/OC1B/PCINT2 – Port B, Bit 2
– SS0: Slave0 Select input. When the SPI0 is enabled as a Slave, this pin is configured as an
input regardless of the setting of DDB2. As a Slave, the SPI0 is activated when this pin is
driven low. When the SPI0 is enabled as a Master, the data direction of this pin is controlled
by DDB2. When the pin is forced by the SPI0 to be an input, the pull-up can still be controlled
by the PORTB2 bit.
– OC1B: Output Compare Match output. The PB2 pin can serve as an external output for the
Timer/Counter1 Compare Match B. The PB2 pin has to be configured as an output (DDB2 set
(one)) to serve this function. The OC1B pin is also the output pin for the PWM mode timer
function.
– PCINT2: Pin Change Interrupt source 2. The PB2 pin can serve as an external interrupt
source.
• OC1A/PCINT1 – Port B, Bit 1
– OC1A: Output Compare Match output. The PB1 pin can serve as an external output for the
Timer/Counter1 Compare Match A. The PB1 pin has to be configured as an output (DDB1 set
(one)) to serve this function. The OC1A pin is also the output pin for the PWM mode timer
function.
– PCINT1: Pin Change Interrupt source 1. The PB1 pin can serve as an external interrupt
source.
• ICP1/CLKO/PCINT0 – Port B, Bit 0
– ICP1: Input Capture Pin. The PB0 pin can act as an Input Capture Pin for Timer/Counter1.
– CLKO: Divided System Clock. The divided system clock can be output on the PB0 pin. The
divided system clock will be output if the CKOUT Fuse is programmed, regardless of the
PORTB0 and DDB0 settings. It will also be output during reset.
– PCINT0: Pin Change Interrupt source 0. The PB0 pin can serve as an external interrupt
source.
Table 17-3 and Table 17-5 relate the alternate functions of Port B to the overriding signals shown in
Figure 17-5. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute the MISO signal, while MOSI is
divided into SPI MSTR OUTPUT and SPI SLAVE INPUT.
ATmega328PB
I/O-Ports
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001906C-page 108