CS43L42

DS481PP2

23

4.10.3 PEAK SIGNAL LIMITER ENABLE (LIM_EN)

Default = 0

0 - Disabled

1 - Enabled

Function:

The CS43L42 will limit the maximum signal amplitude to prevent clipping when this function is enabled.

Peak Signal Limiting is performed by first decreasing the Bass and Treble Boost Levels. If the signal is

still clipping, the digital attenuation is increased. The attack rate is determined by the Limiter Attack Rate

register.

Once the signal has dropped below the clipping level, the attenuation is decreased back to the user se-

lected level followed by the Bass Boost being increased back to the user selected level. The release rate

is determined by the Limiter Release Rate register.

Note: The A=B bit should be set to ‘1’ for optimal limiter performance.

4.10.4 ATAPI CHANNEL MIXING AND MUTING (ATAPI)

Default = 1001 - AOUTA/HP_A = L, AOUTB/HP_B = R (Stereo)

Function:

The CS43L42 implements the channel mixing functions of the ATAPI CD-ROM specification. Refer to Ta-

ble 7 and Figure 31 for additional information.

Note:

All mixing functions occur prior to the digital volume control.

ATAPI3

ATAPI2

ATAPI1

ATAPI0

AOUTA/HP_A

AOUTB/HP_B

0

0

0

0

MUTE

MUTE

0001

MUTE

R

0010

MUTE

L

0011

MUTE

[(L+R)/2]

0100

R

MUTE

0101

R

R

0110

R

L

0

1

1

1

R

[(L+R)/2]

1000

L

MUTE

1001

L

R

1010

L

L

1

0

1

1

L

[(L+R)/2]

1

1

0

0

[(L+R)/2]

MUTE

1101

[(L+R)/2]

R

1110

[(L+R)/2]

L

1

1

1

1

[(L+R)/2]

[(L+R)/2]

Table 7. ATAPI Decode