Advanced Information
WM9707
MUTE
MX4...MX0
0 0000
FUNCTION
0
0
0
1
0dB attenuation
1.5dB attenuation
46.5dB attenuation
∞dB attenuation
0 0001
1 1111
x xxxx
Table 5 Volume Register Function
MASTER TONE CONTROL REGISTERS (INDEX 08h)
Optional register for support of tone controls (bass and treble). The WM9707 does not support bass
and treble and writing to this register will have no effect, reading will result in all zeros.
PC BEEP REGISTER (INDEX 0Ah)
This controls the level for the PC-beep input. Each step corresponds to approximately 3dB of
attenuation. The MSB of the register is the mute bit. When this bit is set to 1 the level for that channel
is set at -∞dB.
WM9707 defaults to the PC-beep path being muted, except during reset when the path is open, so
an external speaker should be provided within the PC to alert the user to power on self-test
problems.
MUTE
PV3...PV0
0000
FUNCTION
0
0
1
0dB attenuation
45dB attenuation
∞dB attenuation
1111
xxxx
Table 6 PC-beep Register Function
ANALOGUE MIXER INPUT GAIN REGISTERS (INDEX 0Ch - 18h AND 72h)
This controls the gain/attenuation for each of the analogue inputs and mixer PGA. Each step
corresponds to approximately 1.5dB. The MSB of the register is the mute bit. When this bit is set to 1
the level for that channel is set at -∞dB.
REGISTER 0Eh (MIC VOLUME REGISTER)
This has an extra bit that is for a 20dB boost. When bit 6 is set to 1 the 20dB boost is on. The default
value is 8008h, which corresponds to 0dB gain with mute on.
The default value for the mono registers is 8008h, which corresponds to 0dB gain with mute on. The
default value for stereo registers is 8808h, which corresponds to 0dB gain with mute on.
MUTE
GX4...GX0
00000
FUNCTION
+12dB gain
0dB gain
0
0
0
1
01000
11111
-34.5dB gain
-∞dB gain
xxxxx
Table 7 Mixer Gain Control Register Function
RECORD SELECT CONTROL REGISTER (INDEX 1Ah)
Used to select the record source independently for right and left (see Table 8). The default value is
0000h, which corresponds to Mic in.
WOLFSON MICROELECTRONICS LTD
AI Rev 2.2 January 2001
21
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
