Rainbow-electronics ATtiny43U Manuel d'utilisateur télécharger pdf (Page 113)

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8048B–AVR–03/09

15.2 Register Description

15.2.1 ADCSRB – ADC Control and Status Register B

• 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 112.

15.2.2 ACSR – Analog Comparator Control and Status Register

• 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

Comparator.

• Bit 5 – ACO: Analog Comparator Output

The output of the Analog Comparator is synchronized and then directly connected to ACO. The

synchronization introduces a delay of 1 - 2 clock cycles.

Table 15-1. Analog Comparator Multiplexed Input

ACME ADEN MUX2..0 Analog Comparator Negative Input

0XXXXAIN1

11XXXAIN1

1 0 000 ADC0

1 0 001 ADC1

1 0 010 ADC2

1 0 011 ADC3

Bit 7 6543210

0x03 (0x23)

BS ACME – ADLAR – ADTS2 ADTS1 ADTS0 ADCSRB

Read/Write R R/W R/W R/W R/W R/W R/W R/W

Initial Value 00000000

Bit 76543210

0x08 (0x28) ACD ACBG ACO ACI ACIE – ACIS1 ACIS0 ACSR

Read/Write R/W R/W R/W R/W R/W R R/W R/W

Initial Value 0 0 N/A 0 0 0 0 0

1 2 ... 108 109 110 111 112 113 114 115 116 117 118 ... 181 182

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