sta381bws STMicroelectronics, sta381bws Datasheet - Page 74

• Manufacturer Part Number: sta381bws
• Description: Sound Terminal 2.1-channel High-efficiency Digital Audio System Sound Terminal 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

Register description: New Map
74/168
ERTHx[6:0]. Setting the ERTHx[7] bits to 1 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 anti-clipping mode, the attack and release thresholds are set relative to full-scale. In DRC
mode (bit D0 reg 0x0A set to 1), 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 018937 Rev 2
STA381BWS