STA333BW_11 STMICROELECTRONICS [STMicroelectronics], STA333BW_11 Datasheet - Page 16

STA333BW_11

Manufacturer Part Number

STA333BW_11

Description

Manufacturer

STMICROELECTRONICS [STMicroelectronics]

Datasheet

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Processing data paths

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Processing data paths

Figure 6

processing chain is composed of two consecutive sections. In the first one, dual-channel

processing is implemented and in the second section each channel is fed into the post

mixing block either to generate a third channel (typically used in 2.1 output configuration and

with crossover filters enabled) or to have the channels processed by the DRC block (2.0

output configuration with crossover filters used to define the cut-off frequency of the two

bands).

The first section,

processing. Then a selectable high-pass filter removes the DC level (enabled if HPB = 0).

The left and right channel processing paths can include up to 8 filters, depending on the

selected configuration (bits BQL, BQ5, BQ6, BQ7 and XO[3:0]). By default, four user

programmable, independent filters per channel are enabled, plus the preconfigured

de-emphasis, bass and treble controls (BQL = 0, BQ5 = 0, BQ6 = 0, BQ7 = 0).

If the coefficient sets for the two channels are linked (BQL = 1) it is possible to use the

de-emphasis, bass and treble filters in a user defined configuration (provided the relevant

BQx bits are set). In this case both channels use the same processing coefficients and can

have up to seven filters each. If BQL = 0 the BQx bits are ignored and the fifth, sixth and

seventh filters are configured as de-emphasis, bass and treble controls, respectively.

Figure 6.

Moreover, the common 8th filter can be available on both channels provided the predefined

crossover frequencies are not used, XO[3:0] = 0, and the DRC is not used.

In the second section,

enabled they are fully user-programmable and allow the generation of a third channel

(2.1 outputs). Alternatively, in mode DRC, these blocks are used to split the sub-band and

define the cut-off frequencies of the two bands. A prescaler and a final postscaler allow full

control over the signal dynamics before and after the filtering stages. A mixer function is also

available.

Sampling

frequency=Fs

From

I2S input

interface

and

Left and right processing, section 1

sampling

Figure 7

over

FIR

Figure

Sampling

frequency=2xFs

PreScale

below show the data processing paths inside STA333BW. The whole

Figure

6, begins with a 2x oversampling FIR filter providing 2 * f

If HPB=0

Hi-Pass

Filter

7, mixing and crossover filters are available. If DRC is not

Doc ID 13773 Rev 3

Biquad

If DSPB=0 and C1EQBP=0

If DSPB=0 and C2EQBP=0

Biquad

User Defined Filters

Biquad

and BQL=1

If DEMP=0

If BQ5=1

De-Emph.

Biquad

and BQL=1

If C1TCB=0

BTC: Bass Boost/Cut

TTC: Treble Boost/Cut

If C2TCB=0

BTC: Bass Boost/Cut

TTC: Treble Boost/Cut

If BQ6=1

Biquad

Bass

and BQL=1

IF BQ7=1

Biquad

Treble

STA333BW

audio

STA333BW_11 STMICROELECTRONICS [STMicroelectronics], STA333BW_11 Datasheet - Page 16

STA333BW_11

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