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Alternate functions of port b, Atmega162/v – Rainbow Electronics ATmega162V User Manual

Page 71

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71

ATmega162/V

2513E–AVR–09/03

Alternate Functions Of Port B

The Port B pins with alternate functions are shown in Table 32.

The alternate pin configuration is as follows:

• SCK – 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 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 con-
trolled by the PORTB7 bit.

• MISO – 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 by the SPI to be an input, the pull-up can still be con-
trolled by the PORTB6 bit.

• MOSI – Port B, Bit 5

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 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 con-
trolled by the PORTB5 bit.

• SS/OC3B – 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 con-
trolled 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.

Table 32. Port B Pins Alternate Functions

Port Pin

Alternate Functions

PB7

SCK (SPI Bus Serial Clock)

PB6

MISO (SPI Bus Master Input/Slave Output)

PB5

MOSI (SPI Bus Master Output/Slave Input)

PB4

SS (SPI Slave Select Input)

OC3B (Timer/Counter3 Output Compare Match Output)

PB3

AIN1 (Analog Comparator Negative Input)

TXD1 (USART1 Output Pin)

PB2

AIN0 (Analog Comparator Positive Input)

RXD1 (USART1 Input Pin)

PB1

T1 (Timer/Counter1 External Counter Input)

OC2 (Timer/Counter2 Output Compare Match Output)

PB0

T0 (Timer/Counter0 External Counter Input)

OC0 (Timer/Counter0 Output Compare Match Output)

clk

I/O

(Divided System Clock)