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4 analog comparator 3 control register - ac3con – Rainbow Electronics ATmega64C1 User Manual

Page 263

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263

7647A–AVR–02/08

ATmega32/64/M1/C1

These 3 bits determine the input of the negative input of the analog comparator.
The different setting are shown in

Table 20-6

.

20.4.4

Analog Comparator 3 Control Register – AC3CON

• 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 20-1

.

• Bit 3 – Res: Reserved Bit

This bit is an unused bit in the ATmega32/64/M1/C1, and will always read as zero.

• Bit 2, 1, 0– AC3M2, AC3M1, AC3M0: Analog Comparator 3 Multiplexer register

Table 20-6.

Analog Comparator 2 negative input selection

AC2M2

AC2M1

AC2M0

Description

0

0

0

“Vref”/6.40

0

0

1

“Vref”/3.20

0

1

0

“Vref”/2.13

0

1

1

“Vref”/1.60

1

0

0

Bandgap (1.1V)

1

0

1

DAC result

1

1

0

Analog Comparator Negative Input (ACMPM pin)

1

1

1

Reserved

Bit

7

6

5

4

3

2

1

0

AC3EN

AC3IE

AC3IS1

AC3IS0

-

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 20-7.

Interrupt sensitivity selection

AC3IS1

AC3IS0

Description

0

0

Comparator Interrupt on output toggle

0

1

Reserved

1

0

Comparator interrupt on output falling edge

1

1

Comparator interrupt on output rising edge