WM8962 Datasheet, PDF (109/295 Pages) Wolfson Microelectronics plc – Ultra-Low Power Stereo CODEC with Audio Enhancement DSP, 1W Stereo Class D Speaker Drivers and Ground Referenced Headphone Drivers

WM8962
DAC SOFT MUTE AND UN-MUTE
A signal can be muted and unmuted using the DAC_MUTE register. The type of muting or unmuting
performed (hard or soft) is controlled by the DAC_MUTE_RAMP and DAC_UNMUTE_RAMP
registers.
Note that the DAC is muted by default. To play back an audio signal, this function must first be
disabled by setting the DAC_MUTE bit to zero.
If DAC_MUTE_RAMP = 0 when a signal is muted, any muting of the output volume is instantaneous
(a ‘hard’ mute). If DAC_MUTE_RAMP = 1 (‘soft’ mute), the signal is gradually attenuated until the
volume of the digital signal reaches zero, as illustrated in Figure 32.
Similarly, the hard and soft unmute functions are controlled by the DAC_UNMUTE_RAMP register. If
DAC_UNMUTE_RAMP = 0, the signal gain returns instantaneously to the current PGA gain setting. If
DAC_UNMUTE_RAMP = 1, the signal is gradually boosted until the volume of the digital signal
reaches the current PGA gain setting. This is illustrated in Figure 32.
DAC_UNMUTE_RAMP would typically be enabled when using soft mute during playback of audio
data so that when mute is then disabled, the sudden volume increase will not create pop noise by
jumping immediately to the previous volume level (e.g. resuming playback after pausing during a
track).
DAC_UNMUTE_RAMP would typically be disabled when un-muting at the start of a digital music file,
so that the first part of the track is not attenuated (e.g. when starting playback of a new track, or
resuming playback after pausing between tracks).
DAC_MUTE = 0
DAC_MUTE = 1
DAC_MUTE_RAMP = 0 and DAC_UNMUTE_RAMP = 0
DAC_MUTE = 0
DAC muting and un-muting with soft mute and soft unmute
disabled
(DAC_MUTE_RAMP = 0 and DAC_UNMUTE_RAMP = 0)
DAC_MUTE = 0
DAC_MUTE = 1
DAC_MUTE_RAMP = 1 and DAC_UNMUTE_RAMP = 1
DAC_MUTE = 0
DAC muting and un-muting with soft mute and soft unmute
enabled
(DAC_MUTE_RAMP = 1 and DAC_UNMUTE_RAMP = 1)
Figure 32 DAC Mute Control
Rev 4.3
109