Table 20-8. Analog Comparator 3 Negative Input Selection
AC3M2
AC3M1
AC3M0
Description
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
“Vref”/6.40
“Vref”/3.20
“Vref”/2.13
“Vref”/1.60
Bandgap (1.1V)
DAC result
Analog comparator Negative Input (ACMPM pin)
Reserved
20.4.5 Analog Comparator Status Register – ACSR
Bit
7
AC3IF
R/W
0
6
AC2IF
R/W
0
5
AC1IF
R/W
0
4
AC0IF
R/W
0
3
AC3O
R
2
AC2O
R
1
AC1O
R
0
AC0O
R
ACSR
Read/Write
Initial Value
0
0
0
0
• Bit 7– AC3IF: Analog Comparator 3 Interrupt Flag Bit
This bit is set by hardware when comparator 3 output event triggers off the interrupt mode defined by AC3IS1 and AC3IS0
bits in AC2CON register.
This bit is cleared by hardware when the corresponding interrupt vector is executed in case the AC3IE in AC3CON register
is set. Anyway, this bit is cleared by writing a logical one on it.
This bit can also be used to synchronize ADC or DAC conversions.
• Bit 6– AC2IF: Analog Comparator 2 Interrupt Flag Bit
This bit is set by hardware when comparator 2 output event triggers off the interrupt mode defined by AC2IS1 and AC2IS0
bits in AC2CON register.
This bit is cleared by hardware when the corresponding interrupt vector is executed in case the AC2IE in AC2CON register
is set. Anyway, this bit is cleared by writing a logical one on it.
This bit can also be used to synchronize ADC or DAC conversions.
• Bit 5– AC1IF: Analog Comparator 1 Interrupt Flag Bit
This bit is set by hardware when comparator 1 output event triggers off the interrupt mode defined by AC1IS1 and AC1IS0
bits in AC1CON register.
This bit is cleared by hardware when the corresponding interrupt vector is executed in case the AC1IE in AC1CON register
is set. Anyway, this bit is cleared by writing a logical one on it.
This bit can also be used to synchronize ADC or DAC conversions.
• Bit 4– AC0IF: Analog Comparator 0 Interrupt Flag Bit
This bit is set by hardware when comparator 0 output event triggers off the interrupt mode defined by AC0IS1 and AC0IS0
bits in AC0CON register.
This bit is cleared by hardware when the corresponding interrupt vector is executed in case the AC0IE in AC0CON register
is set. Anyway, this bit is cleared by writing a logical one on it.
This bit can also be used to synchronize ADC or DAC conversions.
• Bit 3– AC3O: Analog Comparator 3 Output Bit
AC3O bit is directly the output of the analog comparator 2.
Set when the output of the comparator is high.
Cleared when the output comparator is low.
• Bit 2– AC2O: Analog Comparator 2 Output Bit
AC2O bit is directly the output of the analog comparator 2.
Set when the output of the comparator is high.
Cleared when the output comparator is low.
ATmega16/32/64/M1/C1 [DATASHEET]
231
7647O–AVR–01/15
MICROCHIP [ MICROCHIP ]
