WM8955BLGECOSLASHV datasheet(17/44 Pages) WOLFSON

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Production Data

WM8955BL

PD Rev 4.1 February 2007

DIGITAL VOLUME CONTROL

The WM8955BL has on-chip digital attenuation from –127dB to 0dB in 0.5dB steps, allowing the user

to adjust the volume of each channel separately. The level of attenuation for an eight-bit code X is

given by:

-0.5

× (255 – X) dB for 1 ≤ X ≤ 255;

MUTE for X = 0

The LDVU and RDVU control bits control the loading of digital volume control data. When LDVU or

RDVU are set to 0, the LDACVOL or RDACVOL control data is loaded into an intermediate register,

but the actual gain does not change. Both left and right gain settings are updated simultaneously

when either LDVU or RDVU are set to 1.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

7:0

LDACVOL[7:0]

11111111

( 0dB )

Left DAC Digital Volume Control

0000 0000 = Digital Mute

0000 0001 = -127dB

0000 0010 = -126.5dB

... 0.5dB steps up to

1111 1111 = 0dB

R10 (0Ah)

Left Channel

Digital Volume

LDVU

Left DAC Volume Update

0 = Store LDACVOL in intermediate

latch (no gain change)

1 = Update left and right channel

gains (left = LDACVOL, right =

intermediate latch)

7:0

RDACVOL[7:0]

11111111

( 0dB )

Right DAC Digital Volume Control

similar to LDACVOL

R11 (0Bh)

Right Channel

Digital Volume

RDVU

Right DAC Volume Update

0 = Store RDACVOL in intermediate

latch (no gain change)

1 = Update left and right channel

gains (left = intermediate latch,

right = RDACVOL)

Table 3 Digital Volume Control

WM8955BLGECO/V 数据表(PDF) 17 Page - Wolfson Microelectronics plc

WM8955BLGECO/V 数据表(HTML) 17 Page - Wolfson Microelectronics plc

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