WM8961
Pre-Production
REGISTER
SETTING
COMMENT
Reset device if required
0x0F - write
0x0000
0x0F - read
0x08 - write
0x52 - write
0x57 - write
-
Read Chip ID (=0x1801)
0x01F4
0x0003
0x0020
Enable system clocks
Headphone Class W power switching
Enable the write sequencer, DAC to headphone
playback with -20dB volume setting.
0x5A - write
0x0080
Start the write sequencer to configure pre-programmed
enable of the DAC playback (digital input to headphone
output) path. Analogue input PGAs still muted.
Allow enough time for the sequencer to finish
0x5D - read
-
Read status of write sequencer and wait until the
WSEQ_BUSY,bit0,=0 which indicates that the DAC
playback path has been configured. Then continue.
0x1A - write
0x33 - write
0x31 - write
0x28 - write
0x01FC
0x0001
0x00C0
0x0079
Enable the Speaker PGAs, SPKL_PGA and SPKR_PGA
Program the CLASSD_ACGAIN to x1.5
Enable the speakers SPKR_ENA and SPKL_ENA
Set the left speaker volume SPKLVOL to 0dB (which
defaults to mute), change on zero cross only
0x29 - write
0x0079
Set the right speaker volume SPKRVOL to 0dB (which
defaults to mute), change on zero cross only
0x29 - write
0x0179
Update speaker volume SPKVU
Table 69 Register Settings for DAC to Speaker and headphone Outputs
The above configuration enables the speaker and the headphone outputs.
SWITCHING BETWEEN HEADPHONE AND SPEAKERS
With DAC to speaker and headphone playback enabled, switching between headphone and speaker
outputs should be done using the PGA and mute bits as shown in Table 70 and Table 71. This
achieves best pop-click performance.
To save power, it may also be desirable to apply power management settings in addition to the
settings shown, however note that disabled PGAs leave a resistive path hence do not achieve the
published mute attenuation specifications.
0x02 - write
0x03 - write
0x28 - write
0x29 - write
0x012F
0x012F
0x0079
0x0179
Headphone L mute
Headphone R mute
Set the left speaker volume SPKRVOL to 0dB
Set the right speaker volume to 0dB and update speaker
volume SPKVU
Table 70 Switching from Headphone playback to Speaker Playback
PP, August 2009, Rev 3.1
112
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
