Datasheet
65
8197C–AVR–05/11
ATtiny261A/461A/861A
10.2.2 Alternate Functions of Port B
The Port B pins with alternate function are shown in Table 10-6.
• Port B, Bit 7 – RESET
/dW/ADC10/PCINT15
• RESET, Reset pin: When the RSTDISBL Fuse is programmed, this pin functions as a normal
I/O pin, and the part will have to rely on Power-on Reset and Brown-out Reset as its reset
sources. When the RSTDISBL Fuse is unprogrammed, the reset circuitry is connected to the
pin, and the pin can not be used as an I/O pin.
• If PB7 is used as a reset pin, DDB7, PORTB7 and PINB7 will all read 0.
• dW: When the debugWIRE Enable (DWEN) Fuse is programmed and Lock bits are
unprogrammed, the RESET port pin is configured as a wire-AND (open-drain) bi-directional
I/O pin with pull-up enabled and becomes the communication gateway between target and
emulator.
Table 10-6. Port B Pins Alternate Functions
Port Pin Alternate Function
PB7
RESET
: Reset pin
dW: debugWire I/O
ADC10: ADC Input Channel 10
PCINT15:Pin Change Interrupt 0, Source 15
PB6
ADC9: ADC Input Channel 9
T0: Timer/Counter0 Clock Source
INT0: External Interrupt 0 Input
PCINT14:Pin Change Interrupt 0, Source 14
PB5
XTAL2: Crystal Oscillator Output
CLKO: System Clock Output
OC1D: Timer/Counter1 Compare Match D Output
ADC8: ADC Input Channel 8
PCINT13:Pin Change Interrupt 0, Source 13
PB4
XTAL1: Crystal Oscillator Input
CLKI: External Clock Input
OC1D
: Inverted Timer/Counter1 Compare Match D Output
ADC7: ADC Input Channel 7
PCINT12:Pin Change Interrupt 0, Source 12
PB3
OC1B: Timer/Counter1 Compare Match B Output
PCINT11:Pin Change Interrupt 0, Source 11
PB2
USCK: USI Clock (Three Wire Mode)
SCL : USI Clock (Two Wire Mode)
OC1B
: Inverted Timer/Counter1 Compare Match B Output
PCINT10:Pin Change Interrupt 0, Source 10
PB1
DO: USI Data Output (Three Wire Mode)
OC1A: Timer/Counter1 Compare Match A Output
PCINT9: Pin Change Interrupt 1, Source 9
PB0
DI: USI Data Input (Three Wire Mode)
SDA: USI Data Input (Two Wire Mode)
OC1A
: Inverted Timer/Counter1 Compare Match A Output
PCINT8: Pin Change Interrupt 1, Source 8