AD1985 Analog Devices, AD1985 Datasheet - Page 19

• Manufacturer Part Number: AD1985
• Description: AC'97 2.3 Soundmax Codec W/jack Sensing
• Manufacturer: Analog Devices

Phone_in Volume (Index 0x0C)
Reg Num
0x0C
PHV[4:0]
PHM
Volume Settings for Phone and MIC
D15
0
0
0
1
Note: x in the above table is a wild card, meaning the value has no effect.
Microphone Volume (Index 0x0E)
Reg Num
0x0E
This register controls the volume, gain boost, and mute for the
gain/attenuators on both the left (MIC1) and right (MIC2) paths
to the mixer. There is no separate control for left and right on
MCV[4:0]
M20
MCM
Control Bits D[4:0]
Phone (0x0C) and MIC (0x0E)
WRITE
0 0000
0 1000
1 1111
x xxxx
Name
Phone_in Volume
Name
Mic Volume
READBACK
0 0000
0 1000
1 1111
x xxxx
MIC Volume. Allows setting the MIC volume gain/attenuator to one of 32 levels. The LSB represents 1.5 dB, and the
gain range is +12 dB to –34.5 dB. The default value is 0 dB, with mute enabled.
MIC Gain Boost. This bit allows setting additional MIC gain to increase the microphone sensitivity.
The nominal gain boost by default is +20 dB, however Bits D0 and D1 (MBG[1:0]) on the Miscellaneous Control Bits
Register (0x76), allow changing the gain boost to +10 dB or +30 dB if necessary.
0 = Disabled; Gain = 0 dB
1 = Enabled; Default Gain = +20 dB (see Register 0x76, Bits D0, D1)
MIC Mute. When this bit is set to 1, both channels are muted.
Phone Volume. Allows setting the Phone Volume gain/attenuator to one of 32 levels. The LSB represents 1.5 dB,
and the gain range is +12 dB to –34.5 dB. The default value is 0 dB, with mute bit enabled.
Phone Mute. When this bit is set to 1, the Phone channel is muted.
D15
MCM X
D14 D13 D12 D11 D10 D9 D8 D7 D6
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4
PHM X
Function
12 dB Gain
0 dB Gain
–34.5 dB Gain
–∞
X
dB Gain, Muted
X
X
X
X
X
X
Rev. 0 | Page 19 of 48
X
X
X
X
X
this path. The signal paths must be identical, hence the single
control for both.
X
M20 X
X
D5 D4
X
X
MCV4 MCV3 MCV2 MCV1 MCV0
PHV4 PHV3 PHV2 PHV1 PHV0 0x8008
D3
D3
D2
D2
D1
D1
D0
D0
AD1985
Default
0x8008
Default