User Manual

CS4202
24 DS549PP2
4.6 Microphone Volume Register (Index 0Eh)
Mute Microphone Mu te. Settin g this bit mutes th e MIC1 or MIC2 sig nal. The selection of the MIC1
or MIC2 input pin is controlled by the MS bit in the General Purpose Register (Index 20h).
20dB Microphone 20 dB Boost. When ‘set’, the 20dB bit enables the +20 dB microphone boost
block. In combination with the 10dB boost bit in the Misc. Crystal Control Register (Index 60h)
this bit allows for variable boost from 0 dB to +30 dB in steps of 10 dB. Table 3 summarizes
this behavior.
GN[4:0] Microphone Volum e Control. Th e GN[4:0] bits are used to control the gain leve l of the Micro-
phone input source to the Input Mixer. Each step corresponds to 1.5 dB gain adjustment, with
01000 = 0 dB. The total range is +1 2 dB to -34.5 dB gain. See Table 3 for further details.
Default 8008h. This value corresponds to 0 dB gain and Mute ‘set’.
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Mute0000000020dB 0 GN4 GN3 GN2 GN1 GN0
GN4 - GN0
Gain Level
10dB = 0,
20dB = 0
10dB = 1,
20dB = 0
10dB = 0,
20dB = 1
10dB = 1,
20dB = 1
00000 +12.0 dB +22.0 dB +32.0 dB +42.0 dB
00001 +10.5 dB +20.5 dB +30.5 dB +40.5 dB
… … ... ... ...
00111 +1.5 dB +11.5 dB +21.5 dB +31.5 dB
01000 0.0 dB +10.0 dB +20.0 dB +30.0 dB
01001 -1.5 dB +8.5 dB +18.5 dB +28.5 dB
… … ... ... ...
11111 -34.5 dB -24.5 dB -14.5 dB -4.5 dB
Table 3. Microphone Input Gain Values