CS4297 Datasheet, PDF (24/46 Pages) Cirrus Logic – CrystalClear SoundFusion Audio Codec 97

CS4297
CrystalClear™ SoundFusion™ Audio Codec ’97
PC_BEEP Volume (Index 0Ah)
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
X PV3 PV2 PV1 PV0 X
The PC_BEEP Volume control register controls the mix of the PC_BEEP in the Analog Output Mixer.
Each register step corresponds to 3.0 dB volume adjustment, thus offering a range between 0 dB and 45 dB
of attenuation. The MSB of this register controls a master analog mute for the PC_BEEP. Bits PV3 - PV0
of the register control the actual volume levels.
NOTE: The 4 valid data bits for the PC_BEEP volume control are not aligned to the least significant bits
of the register. Valid data bit 0 (PV0) corresponds to bit D1 of the register. Also, each step of the value
(PV3 - PV0) corresponds to a 3 dB step in volume control, as opposed to all other gain controls, which
have a 1.5 dB step size.
Also note that the default state of the mute bit (bit D15) is ‘cleared’, meaning that the PC_BEEP is un-
muted on power-up.
Phone_In Volume (Index 0Ch)
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
X GN4 GN3 GN2 GN1 GN0
This register controls the gain level of the Phone_In input source to the Ouput mixer. Each register step
corresponds to a 1.5 dB gain adjustment allowing a range of 12 dB to -34.5 dB of gain. The MSB controls
an analog mute for the Phone_In signal.
The default values for Phone_In is 8008h, corresponding to 0 dB attenuation and mute on.
Microphone Volume (Index 0Eh)
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 20dB X GN4 GN3 GN2 GN1 GN0
This register controls the gain level of the Mic_In input source to the Input Mixer. It also controls the
+20 dB gain block which connects to the input volume control and to the Input Record Mux. Each register
step (GN4 - GN0) corresponds to a 1.5 dB gain adjustment allowing a range of 12 dB to -34.5 dB of gain.
The 20dB bit, when ‘set’, enables the 20 dB gain block. The MSB controls an analog mute for the Mic_In
signal. The Mic_In source is selected through the General Purpose register
The default values for MIC_IN is 8008h, corresponding to 0 dB attenuation and mute on.
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