Datasheet

Processing data paths STA559BW
16/67 Doc ID 18190 Rev 1
4 Processing data paths
Figure 6 below shows the data processing paths inside STA559BW. The whole processing
chain can be considered as 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 dual-band DRC
block (2.0 output configuration with crossover filters used to define the cut-off frequency of
the two bands).
The first section contains a 2x oversampling FIR filter providing 2 * f
S
audio processing and
a selectable high-pass filter to remove the DC level (enabled if HPB = 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.