Rainbow Electronics ATtiny26L - Manual (Page 102)

102
ATtiny26(L)
1477B–AVR–04/02
• OC1B/PCINT0 – Port B, Bit 3
OC1B: Output Compare match output: The PB3 pin can serve as an output for the
Timer/Counter1 compare match B. The PB3 pin has to be configured as an output
(DDB3 set (one)) to serve this function. The OC1B pin is also the output pin for the PWM
mode.
PCINT0: Pin Change Interrupt 0 pin. Pin change interrupt is enabled on pin when global
interrupt is enabled, pin change interrupt is enabled and the alternate functions do not
mask the interrupt. The masking alternate function is the output compare match output
OC1B. Digital input is enabled on pin PB3 also in SLEEP modes, if the pin change inter-
rupt is enabled and not masked by the alternate functions.
• SCK/SCL/OC1B/PCINT0 – Port B, Bit 2
SCK: Clock input or output in USI Three-wire mode. When the SPI is enabled this pin is
configured as an input. In the USI Three-wire mode the bit DDRB2 controls the direction
of the pin, output for the Master mode and input for the Slave mode.
SCL: USI External Open-collector Serial Clock for USI Two-wire mode. The SCL pin is
pulled low when PORTB2 is cleared (zero) or USI start condition is detected and
DDRB2 is set (one). Pull-up is disabled in USI Two-wire mode.
OC1B: Inverted Timer/Counter1 PWM Output B: The PB2 pin can serve as an inverted
output for the Timer/Counter1 PWM mode if USI is not enabled. The PB2 pin has to be
configured as an output (DDB2 set (one)) to serve this function.
PCINT1: Pin Change Interrupt 0 pin. Pin change interrupt is enabled on pin when global
interrupt is enabled, pin change interrupt is enabled and the alternate functions do not
mask the interrupt. The masking alternate function are the inverted output compare
match output OC1B and USI clocks SCK/SCL. Digital input is enabled on pin PB2 also
in SLEEP modes, if the pin change interrupt is enabled and not masked by the alternate
functions.
• DO/OC1A/PCINT0 – Port B, Bit 1
DO: Data Output in USI Three-wire mode. Data output (DO) overrides PORTB1 value
and it is driven to the port when the data direction bit DDB1 is set (one). However the
PORTB1 bit still controls the pullup, enabling pullup if direction is input and PORTB1 is
set(one).
OC1A: Output Compare match output: The PB1 pin can serve as an output for the
Timer/Counter1 compare match A. The PB1 pin has to be configured as an output
(DDB1 set (one)) to serve this function. The OC1B pin is also the output pin for the PWM
mode timer function if not used in programming or USI.
PCINT0: Pin Change Interrupt 0 pin. Pin change interrupt is enabled on pin when global
interrupt is enabled, pin change interrupt is enabled and the alternate functions do not
mask the interrupt. The masking alternate functions are the output compare match out-
put OC1A and Data Output (DO) in USI Three-wire mode. Digital input is enabled on pin
PB1 also in SLEEP modes, if the pin change interrupt is enabled and not masked by the
alternate functions.