CS4202 Datasheet, PDF (24/68 Pages) Cirrus Logic – Audio Codec 97 with headphone Amplifier

CS4202
4.6 Microphone Volume Register (Index 0Eh)
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Mute 0
0
0
0
0
0
0
0 20dB 0 GN4 GN3 GN2 GN1 GN0
Mute
20dB
GN[4:0]
Default
Microphone Mute. Setting this bit mutes the MIC1 or MIC2 signal. The selection of the MIC1
or MIC2 input pin is controlled by the MS bit in the General Purpose Register (Index 20h).
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.
Microphone Volume Control. The GN[4:0] bits are used to control the gain level 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 +12 dB to -34.5 dB gain. See Table 3 for further details.
8008h. This value corresponds to 0 dB gain and Mute ‘set’.
GN4 - GN0 _{10dB = 0,}
20dB = 0
00000 +12.0 dB
00001 +10.5 dB
…
…
00111
+1.5 dB
01000
0.0 dB
01001
-1.5 dB
…
…
11111
-34.5 dB
Gain Level
10dB = 1, 10dB = 0,
20dB = 0 20dB = 1
+22.0 dB +32.0 dB
+20.5 dB +30.5 dB
...
...
+11.5 dB +21.5 dB
+10.0 dB +20.0 dB
+8.5 dB +18.5 dB
...
...
-24.5 dB -14.5 dB
10dB = 1,
20dB = 1
+42.0 dB
+40.5 dB
...
+31.5 dB
+30.0 dB
+28.5 dB
...
-4.5 dB
Table 3. Microphone Input Gain Values
24
DS549PP1