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Table 42, Attiny26(l) – Rainbow Electronics ATtiny26L User Manual

Page 98

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98

ATtiny26(L)

1477B–AVR–04/02

• ADC4, ADC3 Port – A, Bit 5, 4

ADC4/ADC3: ADC Input Channel 4 and 3. 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.

• AREF/PCINT1 Port – A, Bit 3

AREF: External Reference for ADC. Pullup and output driver are disabled on PA3 when
the pin is used as an external reference or Internal Voltage Reference (2.56V) with
external capacitor at the AREF pin by setting (one) the bit REFS0 in the ADC Multiplexer
Selection Register (ADMUX).

PCINT1: Pin Change Interrupt 1 pin. Pin change interrupt is enabled on pin when global
interrupt is enabled, pin change interrupt is enabled and the alternate function do not
mask the interrupt. The masking alternate function is the pin usage as an analog refer-
ence for the ADC. Digital input is enabled on pin PA3 also in SLEEP modes, if the pin
change interrupt is enabled and not masked by the alternate function.

Table 42. Overriding Signals for Alternate Functions in PA7..PA4

Signal
Name

PA7/ADC6/
AIN1/PCINT1

PA6/ADC5/
AIN0/PCINT1

PA5/ADC4

PA4/ADC3

PUOE

0

0

0

0

PUOV

0

0

0

0

DDOE

0

0

0

0

DDOV

0

0

0

0

PVOE

0

0

0

0

PVOV

0

0

0

0

DIEOE

PCINT1_ENABLE

(1)

ACSR[ACD]

PCINT1_ENABLE

(1)

ACSR[ACD]

0

0

DIEOV

1

1

0

0

DI

PCINT1

PCINT1

AIO

ADC6 INPUT, AIN1

ADC5 INPUT, AIN0

ADC4 INPUT

ADC3 INPUT