WM8904
Pre-Production
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
DAC Mono Mix
0 = Stereo
DAC Mono Mix
R33 (21h)
DAC Digital
1
12
DAC_MONO
0
1 = Mono (Mono mix output on enabled DAC)
Selects DAC filter characteristics
0 = Normal mode
DAC Sloping
Stopband Filter
11
10
DAC_SB_FILT
0
0
1 = Sloping stopband mode (recommended when fs
24kHz
DAC Soft Mute Ramp Rate
DAC Soft Mute
and Soft Un-Mute
DAC_MUTERA
TE
0 = Fast ramp (fs/2, maximum ramp time is 10.7ms at
fs=48k)
1 = Slow ramp (fs/32, maximum ramp time is 171ms at
fs=48k)
DAC Soft Mute Mode
DAC Soft Mute
and Soft Un-Mute
9
DAC_UNMUTE
_RAMP
0
0 = Disabling soft-mute (DAC_MUTE=0) will cause the
DAC volume to change immediately to DACL_VOL and
DACR_VOL settings
1 = Disabling soft-mute (DAC_MUTE=0) will cause the
DAC volume to ramp up gradually to the DACL_VOL
and DACR_VOL settings
DAC Oversample Rate Select
0 = Low power (normal OSR)
1 = High performance (double OSR)
DAC Soft Mute Control
0 = DAC Un-mute
DAC
Oversampling
Ratio (OSR)
6
3
DAC_OSR128
DAC_MUTE
0
1
DAC Soft Mute
and Soft Un-Mute
1 = DAC Mute
DAC De-Emphasis Control
00 = No de-emphasis
DAC De-Emphasis
2:1
DEEMPH [1:0]
00
01 = 32kHz sample rate
10 = 44.1kHz sample rate
11 = 48kHz sample rate
Register 21h DAC Digital 1
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
ADC Volume Update
Analogue-to-Digital
Converter (ADC)
R36 (24h)
ADC Digital
Volume Left
8
ADC_VU
0
Writing a 1 to this bit causes left and right ADC volume
to be updated simultaneously
Left ADC Digital Volume
00h = Mute
Analogue-to-Digital
Converter (ADC)
7:0
ADCL_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 24h ADC Digital Volume Left
PP, Rev 3.3, September 2012
150
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
