ATmega325PA Atmel Corporation, ATmega325PA Datasheet - Page 211

• Manufacturer Part Number: ATmega325PA
• Manufacturer: Atmel Corporation

22.1
8285D–AVR–06/11
Analog Comparator Multiplexed Input
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
It is possible to select any of the ADC7:0 pins to replace the negative input to the Analog Com-
parator. 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
ADCSRB) 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 Analog Comparator, as shown in
22-1. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the Analog
Comparator.
Table 22-1.
ACME
0
1
1
1
1
1
1
1
1
1
Analog Comparator Multiplexed Input
ADEN
x
1
0
0
0
0
0
0
0
0
MUX2:0
000
001
010
011
100
101
110
111
xxx
xxx
Analog Comparator Negative Input
AIN1
AIN1
ADC0
ADC1
ADC2
ADC3
ADC4
ADC5
ADC6
ADC7
Table
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