Datasheet

94
ATmega640/1280/1281/2560/2561
2549K–AVR–01/07
When the SPI0 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.
PCINT1, Pin Change Interrupt source 1: The PB1 pin can serve as an external interrupt
source.
•SS
/PCINT0 – 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.
Table 43 and Table 44 relate the alternate functions of Port B to the overriding signals
shown in Figure 36 on page 89. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute
the MISO signal, while MOSI is divided into SPI MSTR OUTPUT and SPI SLAVE
INPUT.
PCINT0, Pin Change Interrupt source 0: The PB0 pin can serve as an external interrupt
source.
Table 43. Overriding Signals for Alternate Functions in PB7:PB4
Signal
Name PB7/OC0A/OC1C PB6/OC1B PB5/OC1A PB4/OC2A
PUOE 0 0 0 0
PUOV 0 0 0 0
DDOE 0 0 0 0
DDOV 0 0 0 0
PVOE OC0/OC1C ENABLE OC1B ENABLE OC1A ENABLE OC2A ENABLE
PVOV OC0/OC1C OC1B OC1A OC2A
DIEOE PCINT7 • PCIE0 PCINT6 • PCIE0 PCINT5 • PCIE0 PCINT4 • PCIE0
DIEOV 1 1 1 1
DI PCINT7 INPUT PCINT6 INPUT PCINT5 INPUT PCINT4 INPUT
AIO – – – –