REV. B

AD1981B

–15–

Table IV. Volume Settings for Line-In, CD Volume, AUX, and PCM-Out

Control Bits

Reg. 76h

Line-In (10h), CD (12h), AUX (16h), and PCM-Out (18h)

Left Channel Volume D[12:8]

Right Channel Volume D[4:0]

MSPLT

*

D15 WRITE

READBACK Function

D7

* WRITE

READBACK

Function

00

0 0000

0 0000

12 dB Gain

x

0 0000

0 0000

+12 dB Gain

00

0 1000

0 1000

0 dB Gain

x

0 1000

0 1000

0 dB Gain

00

1 1111

1 1111

34.5 dB Gain

x

1 1111

1 1111

–34.5 dB Gain

01

x xxxx

x xxxx

–

dB Gain, Muted

x

x xxxx

x xxxx

–

dB Gain, Muted

10

1 1111

1 1111

–34.5 dB Gain

1

x xxxx

x xxxx

–

dB Gain,

Right Only Muted

11

x xxxx

x xxxx

–

dB Gain,

0

1 1111

1 1111

–34.5 dB Gain

Left Only Muted

11

x xxxx

x xxxx

–

dB Gain, Left Muted 1

x xxxx

x xxxx

–

dB Gain, Right Muted

*For AC ’97 compatibility, Bit D7 (RM) is available only by setting the MSPLT bit, Register 76h. The MSPLT bit enables separate mute bits for the left and right

channels. If MSPLT is not set, RM bit has no effect.

x in the above table is a wild card and has no effect on the value.

Table V. Settings for Record Select Control

LS [10:8]

Left Record Source

RS [2:0]

Right Record Source

000

MIC

000

MIC

001

CD_L

001

CD_R

010

Muted

010

Muted

011

AUX_L

011

AUX_R

100

LINE_IN_L

100

LINE_IN_R

101

Stereo Mix (L)

101

Stereo Mix (R)

110

Mono Mix

110

Mono Mix

111

PHONE_IN

111

PHONE_IN

RS[2:0]

Right Record Select

LS[2:0]

Left Record Select

Record Select Control Register (Index 1Ah)

Reg

No. Name

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

Default

1Ah Record Select

X

X

X

X

X

LS2

LS1

LS0

X

X

X

X

X

RS2

RS1

RS0

0000h

All registers not shown and bits containing an X are assumed to be reserved. Used to select the record source independently for right and left. The default value is

0000h, which corresponds to MIC In. Refer to Table V for examples.