WM8944BECSSLASHR datasheet(33/165 Pages) CIRRUS

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WM8944B

Rev 4.3

3D SURROUND

3D surround

5-notch filter

DF1 filter

L/HPF

Signal Enhancement Block 1 (SE1)

The 3D-stereo surround effect is part of the SE1 block. This function uses time delays and controlled

cross-talk mechanisms to adjust the depth or width of the stereo audio. The 3D-stereo surround effect

includes programmable high-pass or low-pass filtering to limit the 3D effect to specific frequency

bands if required. The structure of the 3D surround processing is illustrated in Figure 13.

HPF

LPF

bypass

HPF

LPF

bypass

-n

forward_l

forward_r

cross_r

cross_l

Figure 13 3D Surround Processing

The 3D surround depth is programmable; the default setting is OFF. The 3D surround processing can

also be configured to create a mono mix of the Left and Right channels in the ADC path.

Note that the 3D surround processing can only be used with the stereo digital microphone in the ADC

path.

The 3D enhancement is enabled on the left and right channels using the SE1_3D_L_ENA and

SE1_3D_R_ENA register bits defined in Table 13. (Note that these bits can be enabled independently

of each other.)

The 3D enhancement coefficients are programmed in registers R68 to R70. For the derivation of

these registers, refer to the configuration tools supplied with the WM8944B Evaluation Kit.

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