attiny25v ATMEL Corporation, attiny25v Datasheet - Page 123

• Manufacturer Part Number: attiny25v
• Description: Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

16. Analog Comparator
16.1
2586K–AVR–01/08
Analog Comparator Multiplexed Input
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 16-1. Analog Comparator Block Diagram
Notes:
See
When the Analog to Digital Converter (ADC) is configurated as single ended input channel, it is
possible to select any of the ADC3..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
16-1. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the Analog
Comparator.
Table 16-1.
Figure
ADC MULTIPLEXER
ACME
Figure 1-1 on page 2
INTERNAL 1.1V
REFERENCE
0
1
1
1
1
1
ACME
ADEN
OUTPUT
1. See
16-1.
(1)
Analog Comparator Multiplexed Input
Table 16-1
ACBG
ADEN
x
1
0
0
0
0
below.
and
MUX1..0
Table 10-5 on page 65
00
01
10
11
xx
xx
Analog Comparator Negative Input
AIN1
AIN1
ADC0
ADC1
ADC2
ADC3
for Analog Comparator pin placement.
ATtiny25/45/85
Table
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