Datasheet

84
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
CLKO, Divided System Clock: The divided system clock can be output on the PB1 pin. The
divided system clock will be output if the CKOUT Fuse is programmed, regardless of the
PORTB1 and DDB1 settings. It will also be output during reset.
PCINT9, Pin Change Interrupt source 9: The PB1 pin can serve as an external interrupt source.
• T0/XCK0/PCINT8, Bit 0
T0, Timer/Counter0 counter source.
XCK0, USART0 External clock. The Data Direction Register (DDB0) controls whether the clock
is output (DDD0 set “one”) or input (DDD0 cleared). The XCK0 pin is active only when the
USART0 operates in Synchronous mode.
PCINT8, Pin Change Interrupt source 8: The PB0 pin can serve as an external interrupt source.
Table 14-7 and Table 14-8 relate the alternate functions of Port B to the overriding signals
shown in Figure 14-5 on page 78. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute the
MISO signal, while MOSI is divided into SPI MSTR OUTPUT and SPI SLAVE INPUT.
Table 14-7. Overriding Signals for Alternate Functions in PB7:PB4.
Signal
name
PB7/SCK/
PCINT15
PB6/MISO/
PCINT14
PB5/MOSI/
PCINT13
PB4/SS/OC0B/
PCINT12
PUOE SPE • MSTR
SPE • MSTR SPE • MSTR SPE • MSTR
PUOV PORTB7 • PUD PORTB14 • PUD PORTB13 • PUD PORTB12 • PUD
DDOE SPE • MSTR SPE • MSTR SPE • MSTR SPE • MSTR
DDOV 0 0 0 0
PVOE SPE • MSTR SPE • MSTR
SPE • MSTR OC0A ENABLE
PVOV SCK OUTPUT
SPI SLAVE
OUTPUT
SPI MSTR OUTPUT OC0A
DIEOE PCINT15 • PCIE1 PCINT14 • PCIE1 PCINT13 • PCIE1 PCINT12 • PCIE1
DIEOV1111
DI
SCK INPUT
PCINT17 INPUT
SPI MSTR INPUT
PCINT14 INPUT
SPI SLAVE INPUT
PCINT13 INPUT
SPI SS
PCINT12 INPUT
AIO––––