CS4297
CrystalClear™ SoundFusion™ Audio Codec ’97
Reset Register (Index 00h)
Any write to this register causes a Register Reset of the AC’97 Registers to occur. This forces all registers
to return to their default state. Reads from the Reset Register will return configuration information about
the part. The CS4297 supports 18-bit DAC and ADC digital audio channels and the Headphone Output (in
the form of the Alternate Line Output). The value read from this register will always be 0x0150h.
Master Volume (Index 02h)
The Master Volume control register controls the LINE_OUT signal’s volume. Each register step corre-
sponds to 1.5 dB volume adjustment, thus offering a range between 0 dB and 94.5 dB of attenuation.
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Mute
X
ML5
ML4
ML3
ML2
ML1
ML0
X
X
MR5 MR4 MR3 MR2 MR1 MR0
Mute - The MSB of this register controls a master analog mute for the LINE_OUT_L and the
LINE_OUT_R output signals.
ML5 - ML0 - These bits control the left channel’s volume
MR5 - MR0 - These bits control the right channel’s volume.
The default value for this register is 8000h, corresponding to 0 dB attenuation and mute on.
Alternate Volume (Index 04h)
The Alternate Volume control register is used to control the ALT_LINE_OUT signal’s volume. Each reg-
ister step corresponds to 1.5 dB volume adjustment, thus offering a range between 0 dB and 94.5 dB of
attenuation.
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Mute
X
ML5
ML4
ML3
ML2
ML1
ML0
X
X
MR5 MR4 MR3 MR2 MR1 MR0
Mute - The MSB of this register controls a master analog mute for the ALT_LINE_OUT_L and the
ALT_LINE_OUT_R output signals.
ML5 - ML0 - These bits control the left channel’s volume.
MR5 - MR0 - These bits control the right channel’s volume.
The default value for this register is 8000h, corresponding to 0 dB attenuation and mute on.
Master Mono Volume (Index 06h)
The Master Mono Volume control register controls the MONO_OUT signal’s volume. Each register step
corresponds to 1.5 dB volume adjustment, thus offering a range between 0 dB and 94.5 dB of attenuation.
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Mute
X
X
X
X
X
X
X
X
X
MM5 MM4 MM3 MM2 MM1 MM0
The MSB of this register controls a master analog mute for the MONO_OUT. Bits MM5 - MM0 of the
register are used to control the actual volume levels.
The default value for this register is 8000h, corresponding to 0 dB attenuation and mute on.
DS242F5
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CIRRUS [ CIRRUS LOGIC ]
