AD1888

Rev. A | Page 16 of 32

Table 19. PCM-Out Volume Register (Index 18h)

Reg

No.

Name

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

Default

18h

PCM

Out

Volume

OM

X

X

LOV4

LOV3

LOV2

LOV1

LOV0

OMRM1

X

X

ROV4

ROV3

ROV2

ROV1

ROV0

8808h

If MSPLT is not set, Bit D7 has no effect. All registers not shown and bits containing an X are assumed to be reserved. Refer to Table 20 for examples.

Note that depending on the state of the AC97NC bit in Register 76h, this register has the following additional functionality:

For AC97NC = 0, the register also controls the Surround, Center, and LFE DAC Gain/Attenuators.

For AC97NC = 1, the register controls the PCM Out Volume only.

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

gain range is +12 dB to −34.5 dB. The default value is 0 dB, mute enabled.

OMRM

Right Channel Mute. Once enabled by the MSPLT bit in Register 76h, this bit mutes the right channel separately from the AVM

bit. Otherwise, this bit will always read 0 and will have no affect 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 the left and the right channels are muted, unless the MSPLT bit in Register

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

Table 20. Volume Settings for Line-In, CD Volume, AUX, and PCM-Out

Reg. 76h

Control Bits

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

Left Channel Volume D[12:8]

Right Channel Volume D[4:0]

MSPLT

T

1

D15

WRITE

READBACK

Function

WRITE

READBACK

Function

0

0

0 0000

0 0000

12 dB Gain

x

0 0000

0 0000

12 dB Gain

0

0

0 1000

0 1000

0 dB Gain

x

0 1000

0 1000

0 dB Gain

0

0

1 1111

1 1111

−34.5 dB Gain

x

1 1111

1 1111

−34.5 dB Gain

0

1

x xxxx

x xxxx

−∞ dB Gain, Muted

x

x xxxx

x xxxx

−∞ dB Gain, Muted

1

0

1 1111

1 1111

−34.5 dB Gain

1

x xxxx

x xxxx

−∞ dB Gain, Right Only Muted

1

1

x xxxx

x xxxx

−∞ dB Gain, Left Only Muted

0

1 1111

1 1111

−34.5 dB Gain

1

1

x xxxx

x xxxx

−∞ dB Gain, Left Muted

1

x xxxx

x xxxx

−∞ dB Gain, Right Muted

If MSPLT is not set, RM Bit has no effect.

x in the above table is don’t care.

Table 21. 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.

Refer to Table 22 for examples. Used to select the record source independently for the right and left channels. For MIC recording, see MS bit (Register 20h) for

MIC1 and MIC2 input selection.

RS [2:0]

Right Record Select

LS [2:0]

Left Record Select