WM8994ECSSLASHR datasheet(103/363 Pages) CIRRUS

103 / 363 page

WM8994

Rev 4.6

103

AIF2 - INPUT PATH VOLUME CONTROL

The AIF2 interface supports two input channels. A digital volume control is provided on each input

signal path, allowing attenuation in the range -71.625dB to 0dB in 0.375dB steps. The level of

attenuation for an eight-bit code X is given by:

0.375

 (X-192) dB for 1  X  192;

MUTE for X = 0

0dB for 192

 X  255

The AIF2DAC_VU bit controls the loading of digital volume control data. When AIF2DAC_VU bit is set

to 0, the AIF2DACL_VOL and AIF2DACR_VOL control data will be loaded into the respective control

updated when a 1 is written to AIF2DAC_VU. This makes it possible to update the gain of left and

right channels simultaneously.

Note that a digital gain function is also available at the audio interface input, to boost the DAC volume

when a small signal

is received on DACDAT2. See “Digital Audio Interface Control” for further details.

Digital volume control is also possible at the DAC stage of the signal path, after the audio signal has

passed through the DAC digital mixers. See

“Digital to Analogue Converter (DAC)” for further details.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R1282

(0502h)

AIF2 DAC

Left Volume

AIF2DAC_V

N/A

AIF2DAC input path Volume Update

Writing a 1 to this bit will cause the AIF2DACL

and AIF2DACR volume to be updated

simultaneously

7:0

AIF2DACL_

VOL [7:0]

C0h

(0dB)

AIF2DAC (Left) input path Digital Volume

00h = MUTE

01h = -71.625dB

… (0.375dB steps)

C0h = 0dB

FFh = 0dB

(See Table 39 for volume range)

R1283

(0503h)

AIF2 DAC

Right Volume

AIF2DAC_V

N/A

AIF2DAC input path Volume Update

Writing a 1 to this bit will cause the AIF2DACL

and AIF2DACR volume to be updated

simultaneously

7:0

AIF2DACR_

VOL [7:0]

C0h

(0dB)

AIF2DAC (Right) input path Digital Volume

00h = MUTE

01h = -71.625dB

… (0.375dB steps)

C0h = 0dB

FFh = 0dB

(See Table 39 for volume range)

Table 44 AIF2 Input Path Volume Control

AIF2 - INPUT PATH SOFT MUTE CONTROL

The WM8994 provides a soft mute function for each of the AIF2 interface input paths. When the soft-

mute function is selected, the WM8994 gradually attenuates the associated signal paths until the path

is entirely muted.

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

setting,

will

gradually

ramp

back

the

digital

gain

setting,

depending

the

AIF2DAC_UNMUTE_RAMP register field.

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

The AIF2 input 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.

WM8994ECS/R Datenblatt(PDF) 103 Page - Cirrus Logic

WM8994ECS/R Datenblatt(HTML) 103 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datenblatt Download

Link URL