ADSP-1981BL AD [Analog Devices], ADSP-1981BL Datasheet - Page 18

• Manufacturer Part Number: ADSP-1981BL
• Description: AC 97 SoundMAX Codec
• Manufacturer: AD [Analog Devices]

AD1981BL
PCM-OUT VOLUME REGISTER
Index 0x18
Reg
No.
0x18
1
Table 21.
Bit
ROV [4:0]
RM
LOV [4:0]
OM
Table 22. Volume Settings for Line-In, CD Volume, AUX, and PCM-Out
Reg. 0x76
MSPLT
0
0
0
0
1
1
1
1
For AC ’97 compatibility, Bit D7 (RM) is available only by setting the MSPLT bit, Register 0x76. The MSPLT bit enables separate mute bits for the left and right channels.
If MSPLT is not set, the RM bit has no effect.
All registers are not shown, and bits containing an X are assumed to be reserved. Refer to Ta
For AC ’97 compatibility, Bit D7 (RM) is available only by setting the MSPLT bit, Register 0x76. The MSPLT bit enables separate mute bits for the left and right channels.
If MSPLT is not set, the RM bit has no effect.
X is a wild card, and has no effect on the value.
1
Name
PCM-Out
Volume
Mnemonic
Right PCM-Out Volume
Right-Channel Mute
Left PCM-Out Volume
PCM-Out Volume Mute
D15
0
0
0
1
0
1
1
D15
OM
D14
X
Left-Channel Volume D [12:8]
Write
0 0000
0 1000
1 1111
X XXXX
1 1111
X XXXX
X XXXX
D13
X
Function
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.
Once enabled by the MSPLT bit in Register 0x76, this bit mutes the right channel separately from
the OM bit. Otherwise, this bit always reads 0 and has no effect when set to 1.
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.
When this bit is set to 1, both the left and right channels are muted unless the MSPLT bit in
Register 0x76 is set to 1, in which case this mute bit affects only the left channel.
D12
LOV4
Line-In (0x10), CD (0x12), AUX (0x16), and PCM-Out (0x18)
Readback
0 0000
0 1000
1 1111
X XXXX
1 1111
X XXXX
X XXXX
D11
LOV3
D10
LOV2
Rev. A | Page 18 of 32
Function
12 dB Gain
0 dB Gain
+34.5 dB
Gain
−∞ dB Gain,
Muted
−34.5 dB
Gain
−∞ dB Gain,
Left Only
Muted
−∞ dB Gain,
Left Muted
D9
LOV1
D8
LOV0
Control Bits
ble 22
D7
RM
D7
X
X
X
X
1
0
1
1
1
for examples.
D6
X
D5
X
Right-Channel Volume D [4:0]
Write
0 0000
0 1000
1 1111
X XXXX
X XXXX
1 1111
X XXXX
D4
ROV4
D3
ROV3
D2
ROV2
1 1111
X XXXX
X XXXX
1 1111
X XXXX
Readback
0 0000
0 1000
D1
ROV1
D0
ROV0
Function
12 dB Gain
0 dB Gain
−34.5 dB
Gain
−∞ dB Gain,
Muted
−∞ dB Gain,
Right Only
Muted
−34.5 dB
Gain
−∞ dB Gain,
Right Muted
Default
0x8808