sta323wqs STMicroelectronics, sta323wqs Datasheet - Page 42

• Manufacturer Part Number: sta323wqs
• Description: 2.1-channel High-efficiency Digital Audio System With Qsound Qhd??
• Manufacturer: STMicroelectronics

Register descriptions
7.5.5
7.5.6
7.5.7
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Post-scale functionality is an attenuation placed after the volume control and directly before
the conversion to PWM. Post-scale can also be used to limit the maximum modulation index
and therefore the peak current. Setting 1, in the PSL register, causes the value stored in
Channel 1 post-scale to be used for all three internal channels.
Biquad coefficient link
Table 33.
For ease of use, all channels can use the biquad coefficients loaded into the channel 1
coefficient RAM space by setting the BQL bit to 1. Therefore, any EQ updates only have to
be performed once.
Dynamic range compression/anti-clipping bit
Table 34.
Both limiters can be used in one of two ways: anti-clipping or dynamic range compression.
When used in anti-clipping mode the limiter threshold values are constant and dependent on
the limiter settings. In dynamic range compression mode the limiter threshold values vary
with the volume settings allowing a nighttime listening mode that provides a reduction in the
dynamic range regardless of the volume level.
Zero-detect mute enable
Table 35.
Setting the ZDE bit enables the zero-detect automatic mute. When ZDE=1, the zero-detect
circuit looks at the input data to each processing channel after the channel-mapping block. If
any channel receives 2048 consecutive zero value samples (regardless of fs) then that
individual channel is muted if this function is enabled.
4
5
6
Bit
Bit
Bit
R/W
R/W
R/W
R/W
R/W
R/W
Biquad coefficient link
Dynamic range compression/anti-clipping bit
Zero-detect mute enable
0
RST
0
RST
1
RST
DRC
BQL
ZDE
Name
Name
Name
Setting of 1 enables the automatic zero-detect mute
0: each channel uses coefficient values
1: each channel uses channel 1 coefficient values
0: limiters act in anti-clipping mode
1: limiters act in dynamic range compression mode
Description
Description
Description
STA323WQS