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STA380BW
Register description: Sound Terminal compatibility
7.16
Extended configuration register (addr 0x36)
The extended configuration register provides access to B
2
DRC and biquad 5, 6 and 7.
7.16.1 Dual-band
DRC
The STA380BW device provides a dual-band DRC (B
2
DRC) on the left and right channel
data path, as depicted in
. The dual-band DRC is activated by setting MDRCE = 1.
Figure 42. B
2
DRC scheme
The low-frequency information (LFE) is extracted from the left and right channels, removing
the high frequencies using a programmable biquad filter, and then computing the difference
with the original signal. Limiter 1 (DRC1) is then used to control the amplitude of the left/right
high-frequency components, while limiter 2 (DRC2) is used to control the low-frequency
components (see
The cutoff frequency of the high-pass filters can be user-defined, XO[3:0] = 0, or selected
from the pre-defined values.
DRC1 and DRC2 are then used to independently limit L/R high frequencies and LFE
channel amplitude (see
) as well as their volume control. To be noted that, in
this configuration, the dedicated channel 3 volume control can actually act as a bass-boost
enhancer as well (0.5 dB/step resolution).
The processed LFE channel is then recombined with the L and R channels in order to
reconstruct the 2.0 output signal.
D7
D6
D5
D4
D3
D2
D1
D0
MDRCE
Reserved
PS48DB
XAR1
XAR2
BQ5
BQ6
BQ7
0
0
0
0
0
0
0
0
B
2
DRC
Hi-pass XO
filter
L
R
B
2
DRC
Hi-pass XO
filter
-
Channel 1
Volume
DRC 1
Channel 3
Volume
DRC 2
+
+
- +
Channel 3
Volume
DRC 2
Channel 2
Volume
DRC 1
+
Obsolete Product(s) - Obsolete Product(s)