sta381bw STMicroelectronics, sta381bw Datasheet - Page 129

• Manufacturer Part Number: sta381bw
• Description: Sound Terminal 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

STA381BW
Register description: Sound Terminal compatibility
automatically selects the anticlipping mode. The release of the limiter, when the gain is
again increased, is dependent on an RMS-detect algorithm. The output of the volume/limiter
block is passed through an RMS filter. The output of this filter is compared to the release
threshold, determined by the release threshold register. When the RMS filter output falls
below the release threshold, the gain is again increased at a rate dependent upon the
release rate register. The gain can never be increased past its set value and, therefore, the
release only occurs if the limiter has already reduced the gain. The release threshold value
can be used to set what is effectively a minimum dynamic range, this is helpful as
overlimiting can reduce the dynamic range to virtually zero and cause program material to
sound “lifeless”.
In AC mode, the attack and release thresholds are set relative to full-scale. In DRC mode,
the attack threshold is set relative to the maximum volume setting of the channels mapped
to that limiter, and the release threshold is set relative to the maximum volume setting plus
the attack threshold.
Doc ID 018835 Rev 2
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