Rainbow Electronics ATtiny26L - Manual (Page 100)

100
ATtiny26(L)
1477B–AVR–04/02
Alternate Functions Of Port B Port B has an alternate functions for the ADC, Clocking, Timer/Counters, USI, SPI pro-
gramming and pin change interrupt. The ADC is described in “Analog to Digital
Converter” on page 77, Clocking in “Architectural Overview” on page 6, timers in
“Timer/Counters” on page 44 and USI in “Universal Serial Interface – USI” on page 63.
Pin change interrupt triggers on pins PB7 - PB0 if interrupt is enabled and it is not
masked by the alternate functions even if the pin is configured as an output. See details
from “Pin Change Interrupt” on page 38. Pin functions in programming modes are
described in “Memory Programming” on page 106. The alternate functions are shown in
Table 44.
The alternate pin configuration is as follows:
• ADC10/RESET/PCINT1 – Port B, Bit 7
ADC10: ADC Input Channel 10. Configure the port pins as inputs with the internal pull-
ups switched off to avoid the digital port function from interfering with the function of the
analog to digital converter.
RESET: External Reset input is active low and enabled by unprogramming (“1”) the
RSTDISBL Fuse. Pullup is activated and output driver and digital input are deactivated
when the pin is used as the RESET pin.
Table 44. Port B Pins Alternate Functions
Port Pin Alternate Functions
PB7 ADC10 (ADC Input Channel 10)
RESET (External Reset Input)
PCINT1 (Pin Change Interrupt 1)
PB6 ADC9 (ADC Input Channel 9)
INT0 (External Interrupt 0 Input)
T0 (Timer/Counter 0 External Counter Clock Input)
PCINT1 (Pin Change Interrupt 1)
PB5 ADC8 (ADC Input Channel 8)
XTAL2 (Crystal Oscillator Output)
PCINT1 (Pin Change Interrupt 1)
PB4 ADC7 (ADC Input Channel 7)
XTAL1 (Crystal Oscillator Input)
PCINT1 (Pin Change Interrupt 1)
PB3 OC1B (Timer/Counter1 PWM Output B, Timer/Counter1Output Compare B Match
Output)
PCINT0 (Pin Change Interrupt 0)
PB2 SCK (USI Clock Input/Output)
SCL (USI External Open-collector Serial Clock)
OC1B (Inverted Timer/Counter1 PWM Output B)
PCINT0 (Pin Change Interrupt 0)
PB1 DO (USI Data Output)
OC1A (Timer/Counter1 PWM Output A, Timer/Counter1 Output Compare A Match
Output)
PCINT0 (Pin Change Interrupt 0)
PB0 DI (USI Data Input)
SDA (USI Serial Data)
OC1A (Inverted Timer/Counter1 PWM Output A)
PCINT0 (Pin Change Interrupt 0)