AD1981BL Analog Devices, AD1981BL Datasheet - Page 15

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

All registers not shown and bits containing an X are assumed to be reserved. Used to select the record source independently for right and left. The default value is
0000h, which corresponds to MIC In. Refer to Table V for examples.
RS[2:0]
LS[2:0]
RIM[3:0]
RM
LIM[3:0]
IM
Reg. 76h
MSPLT* D15 Write
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 is a wild card and has no effect on the value.
REV. 0
*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
Reg
No. Name
1Ah Record Select
Reg
No. Name
1Ch Record Gain
channels. If MSPLT is not set, RM bit has no effect.
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 VI for examples.
0
0
1
0
1
1
LS [10:8]
000
001
010
011
100
101
110
111
Right Channel Mute. Once enabled by the MSPLT bit in Register 76h, this bit mutes the right channel separately
Left Input Mixer Gain Control. Each LSB represents 1.5 dB, 0000 = 0 dB, and the gain range is 0 dB to 22.5 dB.
Right Input Mixer Gain Control. Each LSB represents 1.5 dB, 0000 = 0 dB, and the gain range is 0 dB to 22.5 dB.
from the IM bit. Otherwise, this bit will always read 0 and will have no affect when set to 1.
Input 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 Record Select
Left Record Select
1111
0000
xxxx
1111
xxxx
xxxx
D15
IM
D15
X
Left Channel Input Mixer D[11:8]
D14
X
D14
X
Readback Function
1111
0000
xxxx
1111
xxxx
xxxx
Left Record Source
MIC
CD_L
Muted
AUX_L
LINE_IN_L
Stereo Mix (L)
Mono Mix
PHONE_IN
D13
X
D13
X
D12
X
D12
X
22.5 dB Gain
0 dB Gain
– dB Gain, Muted
22.5 dB Gain
– dB Gain, Left Only Muted 0
– dB Gain, Left Muted
Table VI. Settings for Record Gain Register
Table V. Settings for Record Select Control
Record Select Control Register (Index 1Ah)
D11
LIM3
D11
X
Record Gain Register (Index 1Ch)
LIM2
D10
D10
LS2
Control Bits—Record Gain (1Ch)
D9
LIM1 LIM0
D9
LS1
–15–
RS [2:0]
000
001
010
011
100
101
110
111
D8
D8
LS0
D7* Write Readback
x
x
x
1
1
D7
X
D7
RM* X
1111
0000
xxxx
xxxx
1111
xxxx
D6
X
D6
Right Channel Input Mixer D[3:0]
X
X
D5
D5
1111
0000
xxxx
xxxx
1111
xxxx
D4
X
D4
X
Right Record Source
MIC
CD_R
Muted
AUX_R
LINE_IN_R
Stereo Mix (R)
Mono Mix
PHONE_IN
D3
RIM3 RIM2
D3
X
Function
22.5 dB Gain
0 dB Gain
– dB Gain, Muted
– dB Gain, Right Only Muted
22.5 dB Gain
– dB Gain, Right Muted
D2
D2
RS2
D1
RS1
D1
RIM1
AD1981BL
D0
RS0
D0
RIM0 8000h
Default
0000h
Default