atmega323l ATMEL Corporation, atmega323l Datasheet - Page 126

• Manufacturer Part Number: atmega323l
• Description: Atmega323 8-bit Avr Microcontroller With 32k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Analog Comparator
Multiplexed Input
126
ATmega323(L)
• 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 42.
Table 42. ACIS1/ACIS0 Settings
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.
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 43. If ACME is cleared (zero) or ADEN is set (one),
PB3 (AIN1) is applied to the negative input to the Analog Comparator.
Table 43. Analog Comparator Multiplexed Input
ACME
ACIS1
0
1
1
1
1
1
1
1
1
1
0
0
1
1
ADEN
ACIS0
x
1
0
0
0
0
0
0
0
0
0
1
0
1
Interrupt Mode
Comparator Interrupt on Output Toggle
Reserved
Comparator Interrupt on Falling Output Edge
Comparator Interrupt on Rising Output Edge
MUX2..0
000
001
010
011
100
101
110
111
xxx
xxx
Analog Comparator Negative Input
ADC0
ADC1
ADC2
ADC3
ADC4
ADC5
ADC6
ADC7
AIN1
AIN1
1457G–AVR–09/03