WM1811A datasheet(94/328 Pages) WOLFSON

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WM1811A

Production Data

PD, November 2013, Rev 4.1

AIF2 - INPUT PATH SOFT MUTE CONTROL

The WM1811A provides a soft mute function for the AIF2input paths. When the mute function is

selected, the WM1811A gradually attenuates the associated signal paths until the path is entirely

muted.

When the mute function is de-selected, the gain will either return instantly to the digital gain setting, or

will gradually ramp back to the digital gain setting, depending on the AIF2DAC_UNMUTE_RAMP

The mute and un-mute ramp rate is selectable between two different rates.

The AIF2input paths are soft-muted by default. To play back an audio signal, the soft-mute must first

be de-selected by setting AIF2DAC_MUTE = 0.

The soft un-mute would typically be used during playback of audio data so that when the Mute is

subsequently disabled, a smooth transition is scheduled to the previous volume level and pop noise is

avoided. This is desirable when resuming playback after pausing during a track.

The soft un-mute would typically not be required when un-muting at the start of a music file, in order

that the first part of the music track is not attenuated. The instant un-mute behaviour is desirable in

this case, when starting playback of a new track. See “Digital Volume Soft Mute and Soft Un-Mute”

(Figure 19) for an illustration of the soft mute function.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R1312 (0520h)

AIF2 DAC

Filters (1)

AIF2DAC_

MUTE

AIF2DAC input path Soft Mute Control

0 = Un-mute

1 = Mute

AIF2DAC_

MUTERAT

AIF2DAC input path Soft Mute Ramp Rate

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)

(Note: ramp rate scales with sample rate.)

AIF2DAC_

UNMUTE_

RAMP

AIF2DAC input path Unmute Ramp select

0 = Unmuting the AIF2DAC path

(AIF2DAC_MUTE=0) will immediately apply

the AIF2DACL_VOL and AIF2DACR_VOL

settings.

1 = Unmuting the AIF2DAC path

(AIF2DAC_MUTE=0) will cause a gradual

volume ramp up to the AIF2DACL_VOL and

AIF2DACR_VOL settings.

Table 47 AIF2 Input Path Soft Mute Control

WM1811A Datasheet(PDF) 94 Page - Wolfson Microelectronics plc

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