REV. 0

AD1981A

–12–

AUX Volume (Index 16h)

Reg Num Name

D15 D14 D13

D12

D11

D10

D9

D8

D7

D6 D5

D4

D3

D2

D1

D0

Default

16h

AUX Volume

AM

X

X

LAV4 LAV3 LAV2 LAV1 LAV0 RM

* X

X RAV4 RAV3 RAV2 RAV1 RAV0

8808h

*For AC ‘97 compatibility, Bit D7 (RM) is only available 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.

RAV[4:0]

Right AUX Volume: Allows setting the AUX right channel attenuator in 32 volume levels. The LSB represents

1.5 dB, and the range is +12 dB to –34.5 dB. The default value is 0 dB, mute enabled.

RM

Right Channel Mute: Once enabled by the MSPLT Bit in Register 76h, this bit mutes the right channel separately

from the AM bit. Otherwise, this bit will always read “0” and will have no effect when set to “1.”

LAV[4:0]

Left AUX Volume: Allows setting the AUX left channel attenuator in 32 volume levels. The LSB represents

1.5 dB, and the range is +12 dB to –34.5 dB. The default value is 0 dB, mute enabled.

AM

AUX Mute: When this bit is set to “1,” both L/R channels are muted unless the MSPLT Bit in Register 76h is set

to “1,” in which case this mute bit will only affect the left channel.

PCM Out Volume (Index 18h)

Reg Num Name

D15 D14 D13

D12

D11

D10

D9

D8

D7 D6 D5

D4

D3

D2

D1

D0

Default

18h

PCM Out Vol

OM

X

X

LOV4 LOV3 LOV2 LOV1 LOV0 RM

* X

X ROV4 ROV3 ROV2 ROV1 ROV0 8808h

*For AC ‘97 compatibility, Bit D7 (RM) is only available 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.

ROV[4:0]

Right PCM Out Volume: Allows setting the PCM right channel attenuator in 32 volume levels. The LSB represents

1.5 dB, and the range is +12 dB to –34.5 dB. The default value is 0 dB, mute enabled.

RM

Right Channel Mute: Once enabled by the MSPLT Bit in Register 76h, this bit mutes the right channel separately

from the OM bit. Otherwise, this bit will always read “0” and will have no effect when set to “1.”

LOV[4:0]

Left PCM Out Volume: Allows setting the PCM left channel attenuator in 32 volume levels. The LSB represents

1.5 dB, and the range is +12 dB to –34.5 dB. The default value is 0 dB, mute enabled.

OM

PCM Out Volume Mute: When this bit is set to “1,” both L/R channels are muted unless the MSPLT Bit in

Register 76h is set to “1,” in which case this mute bit will only affect the left channel.

Volume Table (Index 0Ch to 18h)

Mute

x4...x0

Function

0

00000

+12 dB Gain

0

01000

0 dB Gain

0

11111

–34.5 dB Gain

1

xxxxx

–

∞ dB Gain

Record Select Control Register (Index 1Ah)

Reg Num Name

D15 D14 D13 D12 D11 D10

D9

D8 D7 D6 D5 D4 D3

D2

D1

D0 Default

1Ah

Record Select

XXXXX

LS2 LS1 LS0

XXXXX

RS2 RS1 RS0

0000h

NOTES

Used to select the record source independently for right and left. See table for legend.

The default value is 0000h, which corresponds to MIC in.

RS[2:0]

Right Record Select

LS[2:0]

Left Record Select