ATA8742 ATMEL Corporation, ATA8742 Datasheet - Page 150

• Manufacturer Part Number: ATA8742
• Manufacturer: ATMEL Corporation

24. Analog Comparator
24.1
150
Analog Comparator Multiplexed Input
ATA8742
The Analog Comparator compares the input values on the positive pin AIN0 and negative pin
AIN1. When the voltage on the positive pin AIN0 is higher than the voltage on the negative pin
AIN1, the Analog Comparator output, ACO, is set. The comparator can trigger a separate inter-
rupt, exclusive to the Analog Comparator. The user can select Interrupt triggering on comparator
output rise, fall or toggle. A block diagram of the comparator and its surrounding logic is shown
in
Figure 24-1. Analog Comparator Block Diagram
Notes:
When the Analog to Digital Converter (ADC) is configured as single ended input channel, it is
possible to select any of the ADC7..0 pins to replace the negative input to the Analog Compara-
tor. 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), MUX1..0 in ADMUX
select the input pin to replace the negative input to the Analog Comparator, as shown in
24-1. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the Analog
Comparator.
Figure 24-1 on page
ADC MULTIPLEXER
1. See
REFERENCE
ACME
ADEN
BANDGAP
OUTPUT
Table 24-1 on page
(1)
ACBG
150.
151.
(1)
9151A–INDCO–07/09
Table