CS43L42

DS481PP2

21

4.7.4 DE-EMPHASIS CONTROL (DEM)

Default = 00

00 - Disabled

01 - 44.1 kHz

10 - 48 kHz

11 - 32 kHz

Function:

Selects the appropriate digital filter to maintain the standard 15

µs/50 µs digital de-emphasis filter re-

sponse at 32, 44.1 or 48 kHz sample rates. (see Figure 30)

Note:

De-emphasis is not available in High-Rate Mode.

4.7.5 DIGITAL VOLUME CONTROL BYPASS (VCBYP)

Default = 0

0 - Disabled

1 - Enabled

Function:

The digital volume control section is bypassed when this function is enabled. This disables the digital vol-

ume control, muting, bass boost, treble boost, limiting and ATAPI functions. The analog headphone at-

tenuation control will remain functional.

4.8 Limiter Attack Rate (address 08h) (ARATE)

Default = 10h - 2 LRCK’s per 1/8 dB

Function:

The limiter attack rate is user selectable. The rate is a function of sampling frequency, Fs, and the value

in the Limiter Attack Rate register. Rates are calculated using the function RATE = 32/{value}, where

{value} is the decimal value in the Limiter Attack Rate register and RATE is in LRCK’s per 1/8 dB of

change.

Note:

A value of zero in this register is not recommended, as it will induce erratic behavior of the limiter.

Use the LIM_EN bit to disable the limiter function (see Peak Signal Limiter Enable (LIM_EN)).

7

654

32

10

ARATE7

ARATE6

ARATE5

ARATE4

ARATE3

ARATE2

ARATE1

ARATE0

0

001

00

00

Binary Code

Decimal Value

LRCK’s per 1/8 dB

00000001

1

32

00010100

20

1.6

00101000

40

0.8

00111100

60

0.53

01011010

90

0.356

Table 5. Example Limiter Attack Rate Settings