beautypg.com

Atmega169v/l – Rainbow Electronics Atmega169L User Manual

Page 60

background image

60

ATmega169V/L

2514A–AVR–08/02

• SCK/PCINT9 – Port B, Bit 1

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 DDB1.
When the SPI is enabled as a Master, the data direction of this pin is controlled by
DDB1. When the pin is forced to be an input, the pull-up can still be controlled by the
PORTB1 bit.

PCINT9, Pin Change Interrupt Source 9: The PB1 pin can serve as an external interrupt
source.

• SS/PCINT8 – Port B, Bit 0

SS: Slave Port Select input. When the SPI is enabled as a Slave, this pin is configured
as an input regardless of the setting of DDB0. 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 DDB0. When the pin is forced to be an input, the pull-up can still be con-
trolled by the PORTB0 bit

PCINT8, Pin Change Interrupt Source 8: The PB0 pin can serve as an external interrupt
source.

Table 30 and Table 31 relate the alternate functions of Port B to the overriding signals
shown in Figure 25 on page 55. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute
the MISO signal, while MOSI is divided into SPI MSTR OUTPUT and SPI SLAVE
INPUT.

Table 30. Overriding Signals for Alternate Functions in PB7..PB4

Signal
Name

PB7/OC2A/
PCINT15

PB6/OC1B/
PCINT14

PB5/OC1A/
PCINT13

PB4/OC0A/
PCINT12

PUOE

0

0

0

0

PUOV

0

0

0

0

DDOE

0

0

0

0

DDOV

0

0

0

0

PVOE

OC2A ENABLE

OC1B ENABLE

OC1A ENABLE

OC0A ENABLE

PVOV

OC2A

OC1B

OC1A

OC0A

PTOE

DIEOE

PCINT15 •
PCIE1

PCINT14 • PCIE1

PCINT13 • PCIE1

PCINT12 •
PCIE1

DIEOV

1

1

1

1

DI

PCINT15 INPUT

PCINT14 INPUT

PCINT13 INPUT

PCINT12 INPUT

AIO