ATmega88 datasheet(234/340 Pages) ATMEL

234 / 340 page

234

7530H–AVR–02/09

ATmega48/88/168 Automotive

Figure 20-1. Analog Comparator Block Diagram(2)

Notes:

1. See Table 20-2 on page 236.

2. Refer to Figure 1-1 on page 2 and Table 10-9 on page 77 for Analog Comparator pin

placement.

20.0.1

ADC Control and Status Register B – ADCSRB

• Bit 6 – ACME: Analog Comparator Multiplexer Enable

When this bit is written logic one and the ADC is switched off (ADEN in ADCSRA is zero), the

ADC multiplexer selects the negative input to the Analog Comparator. When this bit is written

logic zero, AIN1 is applied to the negative input of the Analog Comparator. For a detailed

description of this bit, see “Analog Comparator Multiplexed Input” on page 236.

20.0.2

Analog Comparator Control and Status Register – ACSR

• Bit 7 – ACD: Analog Comparator Disable

When this bit is written logic one, the power to the Analog Comparator is switched off. This bit

can be set at any time to turn off the Analog Comparator. This will reduce power consumption in

Active and Idle mode. When changing the ACD bit, the Analog Comparator Interrupt must be

disabled by clearing the ACIE bit in ACSR. Otherwise an interrupt can occur when the bit is

changed.

• Bit 6 – ACBG: Analog Comparator Bandgap Select

When this bit is set, a fixed bandgap reference voltage replaces the positive input to the Analog

Comparator. When this bit is cleared, AIN0 is applied to the positive input of the Analog Compar-

ator. See “Internal Voltage Reference” on page 46.

ACBG

BANDGAP

REFERENCE

ADC MULTIPLEXER

OUTPUT

ACME

ADEN

(1)

Bit

6543

210

–

ACME

–

ADTS2

ADTS1

ADTS0

ADCSRB

Read/Write

R/W

Initial Value

0000

000

Bit

76543210

ACD

ACBG

ACO

ACI

ACIE

ACIC

ACIS1

ACIS0

ACSR

Read/Write

R/W

Initial Value

N/A

00000

ATmega88 Datasheet(PDF) 234 Page - ATMEL Corporation

ATmega88 Datasheet(HTML) 234 Page - ATMEL Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL