CS4239 Datasheet, PDF (48/98 Pages) Cirrus Logic – CrystalClear™ Portable ISA Audio System

CS4239
CrystalClear^TM Portable ISA Audio System
Reserved (X0)
Default = xxxxxxxx
D7 D6 D5 D4 D3 D2 D1 D0
rbc rbc rbc rbc rbc rbc rbc rbc
rbc
Reserved, backwards compatible.
Reserved (X1)
Default = xxxxxxxx
D7 D6 D5 D4 D3 D2 D1 D0
rbc rbc rbc rbc rbc rbc rbc rbc
rbc
Reserved, backwards compatible.
MIC Volume (X2)
Default = 01011111
D7 D6 D5 D4 D3 D2 D1 D0
LMIM LMOM MBST MG4 MG3 MG2 MG1 MG0
MG4-MG0
Microphone Gain. The least signifi-
cant bit represents 1.5 dB, where
01111 = 0 dB and 11110 = -22.5 dB.
When all bits are 1, the Mic is muted
with one exception. If MBST = 1
when going from 11110 to 11111, the
Mic volume does not change. The
attenuation steps are shown in
Table 9.
MBST
Microphone 20 dB boost.
When set to 1, the MIC input is
gained by 20 dB.
LMOM
Microphone Left Output Mixer Mute.
When set to 1, the signal to the left
channel output mixer is muted.
LMIM
Microphone Left Input Mixer Mute.
When set to 1, the signal to the left
channel input mixer is muted.
Right Channel MIC (X3)
Default = 01011111
D7 D6 D5 D4 D3 D2 D1 D0
RMIM RMOM MBST MG4 MG3 MG2 MG1 MG0
MG4-MG0
Microphone gain.
The least significant bit represents
1.5 dB, with 01111 = 0 dB. These
are the same bits as in X2.
See Table 9.
MBST
Microphone 20 dB boost.
When set to 1, the MIC input is
gained by 20 dB. This is the same
bit as in X2.
RMOM
Microphone Right Output Mixer Mute.
When set to 1, the signal to the right
channel output mixer is muted.
RMIM
Microphone Right Input Mixer Mute.
When set to 1, the signal to the right
channel input mixer is muted.
Synthesis and Input Mixer Control (X4)
Default = e00exxxx
D7 D6 D5 D4 D3
MIMR LIS1 LIS0 IFM rbc
D2 D1 D0
rbc
res res
IFM
Internal FM enable. When set to 1,
the internal FM synthesis engine is
enabled. This bit can be set through
the Hardware Configuration data in
the EEPROM.
LIS1-LIS0
Left Input Mixer Summer Attenuator.
This attenuates the inputs to the left
input mixer to enable overload pro-
tection when multiple input sources
are utilized.
00 - 0 dB
01 - -6 dB
10 - -12 dB
11 - -18 dB
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DS253PP2