AD1981B Analog Devices, AD1981B Datasheet - Page 14

• Manufacturer Part Number: AD1981B
• Description: AD1981B AC'97 SoundMAX® Codec
• Manufacturer: Analog Devices

AD1981B
RCV[4:0]
RM
LCV[4:0]
CVM
*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
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
bit
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.
AUX Volume
Right CD Volume. Allows setting the CD 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 CVM bit. Otherwise, this bit will always read “0” and will have no affect when set to “1.”
Left CD Volume. Allows setting the CD 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.
CD 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.
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
in Register 76h is set to “1,” in which case this mute bit will affect only the left channel.
D15
AM
D15 D14 D13 D12
D14
X
D13 D12
X
X
LAV4 LAV3 LAV2
LOV4 LOV3 LOV2 LOV1 LOV0 RM* X
D11
D11
PCM-Out Volume Register (Index 18h)
AUX Volume Register (Index 16h)
D10
D10
D9
LAV1 LAV0 RM* X
D9
–14–
D8
D8
D7
D7
D6
D6
D5
X
D5
X
D4
RAV4
D4
ROV4 ROV3 ROV2 ROV1 ROV0 8808h
D3
RAV3 RAV2 RAV1 RAV0 8808h
D3
D2
D2
D1
D1
D0
D0
REV. A
Default
Default