STV82X6 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STV82X6' PDF : 97 Pages View PDF
Audio Processor Block
STV82x6
Table 7: Headphone/Mute Register Configuration
ANA_LS_HP Register
Output Status
HPD_IN
X
X
X
X
0
1
HPD_ON
0
X
X
0
1
1
SW_ON MUTE_LS MUTE_SW MUTE_HP
Muted
Active
0
0
X
0
SW
LS, HP Stereo
1
0
0
1
HP
LS & SW
X
1
1
1
LS, SW & HP (Channel Change: Mute All)
1
0
0
0
LS, SW & HP Mono
0
0
0
0
SW & HP
LS (Default)
0
0
0
0
SW & LS
HP Stereo
3.7 Automatic Loudness Control
As the human ear does not hear the audio frequency range the same way depending on the power
of the audio source, the Loudness Control corrects this effect by sensing the volume level and then
boosting bass and treble frequencies proportionally to middle frequencies at lower volume.
While maintaining the amplitude of the 1 kHz components at an approximately constant value, the
gain values of lower and higher frequencies are automatically progressively amplified up to +18 dB
when the audio volume level decreases.The maximum treble amplification can be adjusted from
0 dB (first order loudness) to +18 dB (second order loudness). As the volume is proportional to the
external audio amplification power, the loudness amplification threshold is programmable in order to
tune the absolute level. The Loudspeaker Loudness function is enabled by setting the LOUD_ON bit
in register LS_LOUD. The Loudness Threshold and Maximum Treble Gain values are also
programmed in this register.
Two bass cut-off frequencies are available:
● 40 Hz for Normal mode
● 120 Hz for Bass Amplified mode
The mode is selected by the LOUD_FREQ bit in register LS_LOUD (66h).
3.8 Subwoofer Control
The subwoofer signal is created by adding the bass frequency of the Left/Right Loudspeaker
channels. The Subwoofer output is enabled by setting the SW_ON bit in register ANA_LS_HP. This
will also force the Headphone output into Mono mode.
The Subwoofer Gain and Frequency Bandwidth values are programmed in registers SW_GAIN and
SW_BAND, respectively. The cut-off frequency can be adjusted from between 50 and 400 Hz in
steps of 50 Hz.
3.9 Beeper
The beeper is used to replace the audio signal with a tone on the Loudspeaker or Headphone
outputs. It can be used for various applications such as beep sounds for remote control, alarm clock
or other features.
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