Pre-Production
WM8904
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
ADC Volume Update
REFER TO
Analogue-to-Digital
Converter (ADC)
R37 (25h)
ADC Digital
Volume
8
ADC_VU
0
Writing a 1 to this bit causes left and right ADC volume
to be updated simultaneously
Right
Right ADC Digital Volume
00h = Mute
Analogue-to-Digital
Converter (ADC)
7:0
ADCR_VOL
[7:0]
1100_0000
01h = -71.625dB
02h = -71.250dB
… (0.375dB steps)
C0h = 0dB
… (0.375dB steps)
EFh to FFh = +17.625dB
Register 25h ADC Digital Volume Right
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
ADC Digital High Pass Filter Cut-Off Frequency (fc)
00 = Hi-fi mode (fc=4Hz at fs=48kHz)
01 = Voice mode 1 (fc=127Hz at fs=16kHz)
10 = Voice mode 2 (fc=130Hz at fs=8kHz)
11 = Voice mode 3 (fc=267Hz at fs=8kHz)
(Note: fc scales with sample rate fs.)
ADC Digital High Pass Filter Enable
0 = disabled
Analogue-to-
Digital Converter
(ADC)
R38 (26h)
ADC Digital
0
6:5
ADC_HPF_CU
T [1:0]
00
Analogue-to-
Digital Converter
(ADC)
4
1
0
ADC_HPF
1
0
0
1 = enabled
Left ADC Invert
Analogue-to-
Digital Converter
(ADC)
ADCL_DATINV
0 = Left ADC output not inverted
1 = Left ADC output inverted
Right ADC Invert
Analogue-to-
Digital Converter
(ADC)
ADCR_DATIN
V
0 = Right ADC output not inverted
1 = Right ADC output inverted
Register 26h ADC Digital 0
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
Enables Digital Microphone mode
0 = Audio DSP input is from ADC
Digital Microphone
Interface
R39 (27h)
Digital
Microphone
0
12
DMIC_ENA
0
1 = Audio DSP input is from digital microphone
interface
When DMIC_ENA = 0, the Digital microphone clock
(DMICCLK) is held low.
Selects Digital Microphone Data Input pin
0 = IN1L/DMICDAT1
Digital Microphone
Interface
11
DMIC_SRC
0
1 = IN1R/DMICDAT2
Register 27h Digital Microphone 0
PP, Rev 3.3, September 2012
151
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
