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- •Errata
ATmega16(L)
Analog
Comparator
Multiplexed Input
Table 79. |
ACIS1/ACIS0 Settings |
||
ACIS1 |
|
ACIS0 |
Interrupt Mode |
|
|
|
|
0 |
|
0 |
Comparator Interrupt on Output Toggle |
|
|
|
|
0 |
|
1 |
Reserved |
|
|
|
|
1 |
|
0 |
Comparator Interrupt on Falling Output Edge |
|
|
|
|
1 |
|
1 |
Comparator Interrupt on Rising Output Edge |
|
|
|
|
When changing the ACIS1/ACIS0 bits, the Analog Comparator Interrupt must be disabled 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 Analog 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 Analog 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 80. Analog Comparator Multiplexed Input
ACME |
ADEN |
MUX2..0 |
Analog Comparator Negative Input |
|
|
|
|
0 |
x |
xxx |
AIN1 |
|
|
|
|
1 |
1 |
xxx |
AIN1 |
|
|
|
|
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 |
|
|
|
|
203
2466P–AVR–08/07