DS640PP4

17

CS44L11

4.5.3

Tone Control Mode (TC)

Default = 00

00 - All settings are taken from user registers

01 - 12 dB of Bass Boost at 100 Hz and 6 dB of Treble Boost at 7 kHz (at LRCK = 48 kHz)

10 - 8 dB of Bass Boost at 100 Hz and 4 dB of Treble Boost at 7 kHz (at LRCK = 48 kHz)

11 - 4 dB of Bass Boost at 100 Hz and 2 dB of Treble Boost at 7 kHz (at LRCK = 48 kHz)

Function:

The Tone Control Mode bits determine how the Bass Boost and Treble Boost features are configured.

The user-defined settings from the Bass and Treble Boost Level and Corner Frequency registers are used

when these bits are set to ‘00’. Alternately, one of three pre-defined settings may be used (these settings

are a function of LRCK - refer to Tables 5, 6, and 7).

Note:

Treble Boost is not available in Double-Speed Mode.

4.5.4

Tone Control Enable (TC_EN)

Default = 0

0 - Disabled

1 - Enabled

Function:

The Bass Boost and Treble Boost features are active when this function is enabled.

4.5.5

Peak Signal Limiter Enable (LIM_EN)

Default = 0

0 - Disabled

1 - Enabled

Function:

The CS44L11 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.