MSP3438G Datasheet, PDF (28/84 Pages) Micronas – Multistandard Sound Processor Family

MSP 3438G
PRELIMINARY DATA SHEET
Table 3–10: Write Registers on I²C Subaddress 12_hex, continued
Register Function
Address
LOUDSPEAKER AND AUX PROCESSING
00 00_hex
00 06_hex
Volume Loudspeaker
Volume Aux
bit [15:8]
volume table with 1 dB step size
7F_hex
7E_hex
...
+12 dB (maximum volume)
+11 dB
74_hex
73_hex
72_hex
...
+1 dB
0 dB
−1 dB
02_hex
01_hex
00_hex
FF_hex
−113 dB
−114 dB
Mute (reset condition)
Fast Mute (needs about 75ms until the signal is com-
pletely ramped down)
bit [7:5]
higher resolution volume table
0
+0 dB
1
+0.125 dB increase in addition to the volume table
...
7
+0.875 dB increase in addition to the volume table
bit [4:0] not used
must be set to 0
Name
VOL_MAIN
VOL_AUX
With large scale input signals, positive volume settings may lead to signal clipping.
00 29_hex
The MSP 34x8G loudspeaker and aux volume function is divided into a digital
and an analog section. With Fast Mute, volume is reduced to mute position by
digital volume only. Analog volume is not changed. This reduces any audible
DC plops. To turn volume on again, the volume step that has been used before
Fast Mute was activated must be transmitted.
Automatic Volume Correction (AVC) Loudspeaker Channel
AVC
bit [15:12] 00_hex
08_hex
bit [11:8]
08_hex
04_hex
02_hex
01_hex
AVC off (and reset internal variables)
AVC on
8 sec decay time
4 sec decay time
2 sec decay time
20 ms decay time (intended for quick adaptation to the
average volume level after channel change)
Note: To reset the internal variables, the AVC should be switched off and then
on again during any channel or source change. For standard applications, the
recommended decay time is 4 sec.
00 34_hex
Note: AVC should not be used in any Dolby Prologic mode.
Preemphasis Aux Channel
bit [15:8] 00_hex
7F_hex
FF_hex
Preemphasis OFF
Preemphasis 50 µ (−3 dB scaling)
Preemphasis 75 µ (−3 dB scaling)
PREEMP_AUX
28
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