26 gain & bias control (address 1dh), 1 pga x preamplifier gain, 2 boostx – Cirrus Logic CS42L56 User Manual
Page 76: 3 microphone bias output level, 1 pga x input select, P 77, Mux bit, Cs42l56
76
DS851F2
CS42L56
6.26 Gain & Bias Control (Address 1Dh)
6.26.1 PGA x Preamplifier Gain
Configures the gain of the PGA x preamp.
6.26.2 Boostx
Configures a +20 dB digital boost on ADC channel x.
6.26.3 Microphone Bias Output Level
Configures the voltage level of the microphone bias output.
6.27 PGA x MUX, Volume: PGA A (Address 1Eh) & PGA B (Address 1Fh)
6.27.1 PGA x Input Select
Selects the specified analog input signal into PGA channel x.
Note:
For pseudo-differential inputs, the CODEC automatically chooses the respective pseudo-ground
(AIN1REF or AIN2REF) for each input selection.
Use the AINx_REF bits (
Analog Input 1 x Reference Configuration
and
“Analog Input 1 x Reference Con-
) to properly configure the input channel.
7
6
5
4
3
2
1
0
PREAMPB1
PREAMPB0
PREAMPA1
PREAMPA0
BOOSTB
BOOSTA
BIAS_LVL1
BIAS_LVL0
PREAMPx[1:0]
PGA x Preamp Gain
00
0 dB
01
+10 dB
10
+20 dB
11
Reserved
BOOSTx
+20 dB Boost
0
No boost applied
1
+20 dB digital boost applied
BIAS_LVL[1:0]
MIC Bias Output Level
00
0.9xVA
01
0.8xVA
10
0.7xVA
11
0.6xVA
7
6
5
4
3
2
1
0
PGAxMUX1
PGAxMUX0
PGAxVOL5
PGAxVOL4
PGAxVOL3
PGAxVOL2
PGAxVOL1
PGAxVOL0
PGAxMUX[1:0]
Selected Input to PGAx
00
AIN1x.
01
AIN2x.
10
AIN3x.
11
Reserved