CS4237B Datasheet, PDF (52/114 Pages) Cirrus Logic – CrystalClear Advanced Audio System with 3D Sound

CS4237B
Left MIC Volume (X2)
Default = 11001111
D7 D6 D5 D4 D3 D2 D1 D0
LMIM LMOM LMBST LMG4 LMG3 LMG2 LMG1 LMG0
LMG4-LMG0
Left Microphone Gain.
The least significant bit represents
1.5 dB, with 01111 = 0 dB.
See Table 13.
LMBST
Left Microphone 20 dB boost.
When set to 1, the signal to the out-
put mixer is given a 20 dB boost.
LMOM
Left Microphone Output Mixer Mute.
When set to 1, the signal to the out-
put mixer is muted.
LMIM
Left Microphone Input Mixer Mute.
When set to 1, the signal to the in-
put mixer is muted.
LMIC
Input
LMG4-G0
LMOM
+20 dB
LMBST
LMIM
+22.5 to -22.5 dB
To Output
Mixer
To Input
Mixer
Right MIC Volume (X3)
Default = 11001111
D7 D6 D5 D4 D3 D2 D1 D0
RMIM RMOM RMBST RMG4 RMG3 RMG2 RMG1 RMG0
RMG4-RMG0
Right Microphone gain.
The least significant bit represents
1.5 dB, with 01111 = 0 dB.
See Table 13.
RMBST
Right Microphone 20 dB boost.
When set to 1, the signal to the out-
put mixer is given a 20 dB boost.
RMOM
Right Microphone Output Mixer Mute.
When set to 1, the signal to the out-
put mixer is muted.
RMIM
Right Microphone Input Mixer Mute.
When set to 1, the signal to the in-
put mixer is muted.
RMIC
Input
RMG4-G0
RMOM
+20 dB
RMBST
RMIM
+22.5 to -22.5 dB
To Output
Mixer
To Input
Mixer
Synthesis and Input Mixer Control (X4)
Default = 100001xx
D7 D6 D5 D4 D3
MIMR LIS1 LIS0 IFM WTRMD
D2
FMRM
D1 D0
res res
res
Reserved. Must write 0. Could be
read as 0 or 1.
FMRM
FM Volume Control Remap. This bit
only functions when IFM = 1.
If FMRM = 1, internal FM Synthesis
volume is controlled by I18/I19
(writes to I18/I19 get remapped to
X6/X7). Analog LINE volume is con-
trolled by X0/X1.
If FMRM = 0, internal FM synthesis
volume is controlled by X6/X7 only.
WTRMD
WaveTable Volume Remap Disable.
This bit only functions when
WTEN = 1 (C8/Global Config. byte).
If WTRMD = 0, the Wavetable Serial
Port volume is controlled by I18/I19
(writes to I18/I19 get remapped to
X16/X17). Analog LINE volume is
controlled by X0/X1.
If WTRMD = 1, the Wavetable Serial
Port volume is controlled by
X16/X17 only.
NOTE: If FMRM = 1, and
WTRMD = 0, I18/I19 control both in-
ternal FM and Wavetable Serial Port
volume.
IFM
Internal FM enable. When set to 1,
the internal FM synthesis engine is
enabled. Setting this bit also
changes I6/7 from the master digital
audio volume to the ISA bus wave
volume control. X14/15 becomes the
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