Datasheet

199
7734Q–AVR–02/12
AT90PWM81/161
16.4.3 AC3CON - Analog Comparator 3 Control Register
• Bit 7– AC3EN: Analog Comparator 3 Enable Bit
Set this bit to enable the analog comparator 3.
Clear this bit to disable the analog comparator 3.
• Bit 6– AC3IE: Analog Comparator 3 Interrupt Enable bit
Set this bit to enable the analog comparator 3 interrupt.
Clear this bit to disable the analog comparator 3 interrupt.
• Bit 5, 4– AC3IS1, AC3IS0: Analog Comparator 3 Interrupt Select bit
These 2 bits determine the sensitivity of the interrupt trigger.
The different setting are shown in Table 16-5.
• Bit 3– AC3OEA: Analog Comparator 3 Alternate Output Enable
Set this bit to enable the analog comparator 3 alternate output pin.
Clear this bit to disable the analog comparator 3 alternate output pin.
• Bit 2, 1, 0– AC3M2, AC3M1, AC3M0: Analog Comparator 3 Multiplexer register
These 3 bits determine the input of the negative input of the analog comparator.
The different setting are shown in Table 16-6.
Bit 7 6543210
AC3EN AC3IE AC3IS1 AC3IS0 AC3OEA AC3M2 AC3M1 AC3M0 AC3CON
Read/Write R/W R/W R/W R/W - R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Table 16-5. Interrupt sensitivity selection.
AC3IS1 AC3IS0 Description
0 0 Comparator interrupt on output toggle
01Reserved
1 0 Comparator interrupt on output falling edge
1 1 Comparator interrupt on output rising edge
Table 16-6. Analog Comparator 2 negative input selection.
AC3M2 AC3M1 AC3M0 Description
000“V
REF
”/6.40
001“V
REF
”/3.20
010“V
REF
”/2.13
011“V
REF
”/1.60
100Band gap voltage
101DAC result
110Analog comparator negative input (ACMPM3 pin)
111Analog comparator negative input (ACMPM pin)