Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller TQFP 44 (10x10) 8-Bit 16 MHz I/O number 32

7674F–AVR–09/09

ATmega164P/324P/644P

12.3.2 Alternate Functions of Port B

The Port B pins with alternate functions are shown in Table 12-6.

The alternate pin configuration is as follows:

• SCK/PCINT15 – Port B, Bit 7

SCK: Master Clock output, Slave Clock input pin for SPI channel. When the SPI is enabled as a

slave, this pin is configured as an input regardless of the setting of DDB7. When the SPI0 is

enabled as a master, the data direction of this pin is controlled by DDB7. When the pin is forced

to be an input, the pull-up can still be controlled by the PORTB7 bit.

PCINT15, Pin Change Interrupt source 15: The PB7 pin can serve as an external interrupt

source.

• MISO/PCINT14 – Port B, Bit 6

MISO: Master Data input, Slave Data output pin for SPI channel. 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 to

be an input, the pull-up can still be controlled by the PORTB6 bit.

PCINT14, Pin Change Interrupt source 14: The PB6 pin can serve as an external interrupt

source.

Table 12-6. Port B Pins Alternate Functions

Port Pin Alternate Functions

PB7

SCK (SPI Bus Master clock input)

PCINT15 (Pin Change Interrupt 15)

PB6

MISO (SPI Bus Master Input/Slave Output)

PCINT14 (Pin Change Interrupt 14)

PB5

MOSI (SPI Bus Master Output/Slave Input)

PCINT13 (Pin Change Interrupt 13)

PB4

(SPI Slave Select input)

OC0B (Timer/Conter 0 Output Compare Match B Output)

PCINT12 (Pin Change Interrupt 12)

PB3

AIN1 (Analog Comparator Negative Input)

OC0A (Timer/Conter 0 Output Compare Match A Output)

PCINT11 (Pin Change Interrupt 11)

PB2

AIN0 (Analog Comparator Positive Input)

INT2 (External Interrupt 2 Input)

PCINT10 (Pin Change Interrupt 10)

PB1

T1 (Timer/Counter 1 External Counter Input)

CLKO (Divided System Clock Output)

PCINT9 (Pin Change Interrupt 9)

PB0

T0 (Timer/Counter 0 External Counter Input)

XCK0 (USART0 External Clock Input/Output)

PCINT8 (Pin Change Interrupt 8)