wm9708 Wolfson Microelectronics plc, wm9708 Datasheet - Page 24

• Manufacturer Part Number: wm9708
• Description: Ac?97 Revision 2.1 Audio Codec
• Manufacturer: Wolfson Microelectronics plc

WM9708
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Table 7 Record Select Register Function
RECORD GAIN REGISTERS (INDEX 1Ch)
1Ch is for the stereo input. Each step corresponds to 1.5dB. 22.5dB corresponds to 0F0Fh. The MSB
of the register is the mute bit. When this bit is set to 1, the level for that channel(s) is set at -
The default value is 8000h, which corresponds to 0dB gain with mute on.
Table 8 Record Gain Register Function
GENERAL PURPOSE REGISTER (INDEX 20h)
This register is used to control several miscellaneous functions of the WM9708.
Below is a summary of each bit and its function. Only the MIX, MS and LPBK bits are supported by
the WM9708. The MS bit controls the Mic selector. The LPBK bit enables loopback of the ADC
output to the DAC input without involving the AC-link, allowing for full system performance
measurements. The function default value is 8000h which is all off.
Table 9 General Purpose Register Function
MUTE
SR2 TO SR0
0
0
1
RLBK
LPBK
LLBK
POP
MIX
MS
ST
3D
LD
0
1
2
3
4
5
6
7
BIT
GX3...GX0
xxxxx
1111
0000
RIGHT RECORD SOURCE
Mic
CD in (R)
Not supported
Not supported
Line in (R)
Stereo mix (R)
Mono mix
Phone
FUNCTION
PCM out path and mute
Simulated stereo enhancement, on/off 1 = on
3D stereo enhancement on/off, 1 = on
Loudness (bass boost) on/off, 1 = on
Local loop back - for modem, line codec
Remote loop back - for modem, line codec
Mono output select 0 = Mix, 1 = Mic
Mic select 0 = Mic1, 1 = Mic2
ADC/DAC loopback mode
FUNCTION
+22.5dB gain
0dB gain
-
∞
dB gain
SL2 TO SL0
0
1
2
3
4
5
6
7
LEFT RECORD SOURCE
Mic
CD in (L)
Not supported
Not supported
Line in (L)
Stereo mix (L)
Mono mix
Phone
PD, Rev 4.2, August 2009
SUPPORT
WM9708
Production Data
Yes
Yes
Yes
Yes
No
No
No
No
No
∞
dB.
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