AD1981BL Analog Devices, AD1981BL Datasheet - Page 14

• Manufacturer Part Number: AD1981BL
• Description: Low Voltage AC'97 Soundmax Codec
• Manufacturer: Analog Devices

*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
AD1981BL
RAV[4:0]
RM
LAV[4:0]
AM
*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
ROV[4:0]
RM
LOV[4:0]
OM
Reg. 76h
MSPLT* D15 Write
0
0
0
0
1
1
1
*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
x in the above table is a wild card and has no effect on the value.
Reg
No. Name
16h
channels. If MSPLT is not set, RM bit has no effect. All registers not shown, and bits containing an X are assumed to be reserved. Refer to Table IV for examples.
Reg
No. Name
18h PCM-Out Volume OM X
channels. If MSPLT is not set, RM bit has no effect. All registers not shown, and bits containing an X are assumed to be reserved. Refer to Table IV for examples.
channels. If MSPLT is not set, RM bit has no effect.
AUX Volume
0
0
0
1
0
1
1
Right AUX Volume. Allows setting the AUX 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.
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 affect when set to 1.
Left AUX Volume. Allows setting the AUX left 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.
AUX Mute. When this bit is set to 1, both the left and 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.
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.
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.
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.
PCM-Out Volume Mute. When this bit is set to 1, both the left and 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.
0 0000
0 1000
1 1111
x xxxx
1 1111
x xxxx
x xxxx
D15
AM
D15 D14 D13 D12
Left Channel Volume D[12:8]
D14
X
Table IV. Volume Settings for Line-In, CD Volume, AUX, and PCM-Out
Readback
0 0000
0 1000
1 1111
x xxxx
1 1111
x xxxx
x xxxx
X
D13 D12
X
LAV4 LAV3 LAV2
LOV4 LOV3 LOV2 LOV1 LOV0 RM* X
Line-In (10h), CD (12h), AUX (16h), and PCM-Out (18h)
D11
D11
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 1
PCM-Out Volume Register (Index 18h)
AUX Volume Register (Index 16h)
D10
D10
LAV1 LAV0 RM* X
D9
D9
–14–
D8
D8
Control Bits
D7* Write
x
x
x
x
1
0
D7
D7
0 0000
0 1000
1 1111
x xxxx
x xxxx
1 1111
x xxxx
D6
D6
D5
X
D5
X
Right Channel Volume D[4:0]
Readback
0 0000
0 1000
1 1111
x xxxx
x xxxx
1 1111
x xxxx
D4
RAV4
D4
ROV4 ROV3 ROV2 ROV1 ROV0 8808h
D3
RAV3 RAV2 RAV1 RAV0 8808h
D3
D2
D2
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
D1
D1
D0
D0
Default
Default
REV. 0