Rainbow-electronics ATmega32L Instrukcja Użytkownika Pobierz pdf (Strona 198)

198

ATmega32(L)

2503C–AVR–10/02

• Bits 1, 0 – ACIS1, ACIS0: Analog Comparator Interrupt Mode Select

These bits determine which comparator events that trigger the Analog Comparator inter-

rupt. The different settings are shown in Table 79.

When changing the ACIS1/ACIS0 bits, the Analog Comparator Interrupt must be dis-

abled by clearing its Interrupt Enable bit in the ACSR Register. Otherwise an interrupt

can occur when the bits are changed.

Analog Comparator

Multiplexed Input

It is possible to select any of the ADC7..0 pins to replace the negative input to the Ana-

log Comparator. The ADC multiplexer is used to select this input, and consequently, the

ADC must be switched off to utilize this feature. If the Analog Comparator Multiplexer

Enable bit (ACME in SFIOR) is set and the ADC is switched off (ADEN in ADCSRA is

zero), MUX2..0 in ADMUX select the input pin to replace the negative input to the Ana-

log Comparator, as shown in Table 80. If ACME is cleared or ADEN is set, AIN1 is

applied to the negative input to the Analog Comparator.

Table 79. ACIS1/ACIS0 Settings

ACIS1 ACIS0 Interrupt Mode

0 0 Comparator Interrupt on Output Toggle

01Reserved

1 0 Comparator Interrupt on Falling Output Edge

1 1 Comparator Interrupt on Rising Output Edge

Table 80. Analog Comparator Multiplexed Input

ACME ADEN MUX2..0 Analog Comparator Negative Input

0xxxxAIN1

11xxxAIN1

1 0 000 ADC0

1 0 001 ADC1

1 0 010 ADC2

1 0 011 ADC3

1 0 100 ADC4

1 0 101 ADC5

1 0 110 ADC6

1 0 111 ADC7

1 2 ... 193 194 195 196 197 198 199 200 201 202 203 ... 312 313

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Rainbow-electronics ATmega32L Instrukcja Użytkownika Strona 198