ATmega48/88/168
(one)) to serve this function. The OC1A pin is also the output pin for the PWM mode timer
function.
PCINT1: Pin Change Interrupt source 1. The PB1 pin can serve as an external interrupt source.
• ICP1/CLKO/PCINT0 – Port B, Bit 0
ICP1, Input Capture Pin: The PB0 pin can act as an Input Capture Pin for Timer/Counter1.
CLKO, Divided System Clock: The divided system clock can be output on the PB0 pin. The
divided system clock will be output if the CKOUT Fuse is programmed, regardless of the
PORTB0 and DDB0 settings. It will also be output during reset.
PCINT0: Pin Change Interrupt source 0. The PB0 pin can serve as an external interrupt source.
Table 13-4 and Table 13-5 relate the alternate functions of Port B to the overriding signals
shown in Figure 13-5 on page 77. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute the
MISO signal, while MOSI is divided into SPI MSTR OUTPUT and SPI SLAVE INPUT.
Table 13-4. Overriding Signals for Alternate Functions in PB7..PB4
Signal
Name
PB7/XTAL2/
PB6/XTAL1/
PB5/SCK/
PCINT5
PB4/MISO/
PCINT4
TOSC2/PCINT7(1)
TOSC1/PCINT6(1)
INTRC • EXTCK+
AS2
PUOE
PUOV
DDOE
INTRC + AS2
0
SPE • MSTR
PORTB5 • PUD
SPE • MSTR
SPE • MSTR
PORTB4 • PUD
SPE • MSTR
0
INTRC • EXTCK+
AS2
INTRC + AS2
DDOV
PVOE
0
0
0
0
0
0
SPE • MSTR
SPE • MSTR
SPI SLAVE
OUTPUT
PVOV
0
0
SCK OUTPUT
PCINT5 • PCIE0
1
INTRC • EXTCK +
AS2 + PCINT7 •
PCIE0
INTRC + AS2 +
PCINT6 • PCIE0
DIEOE
PCINT4 • PCIE0
1
(INTRC + EXTCK) •
AS2
DIEOV
DI
INTRC • AS2
PCINT5 INPUT
SCK INPUT
PCINT4 INPUT
PCINT7 INPUT
Oscillator Output
PCINT6 INPUT
SPI MSTR INPUT
Oscillator/Clock
Input
AIO
–
–
81
2545M–AVR–09/07
ATMEL [ ATMEL ]
