STA350BW Datasheet, PDF (77/86 Pages) STMicroelectronics – Sound Terminal® 2.1-channel high-efficiency digital audio system

STA350BW
Register description
7.21 Extra volume resolution configuration registers (address
0x3F)
D7
VRESEN
0
D6
VRESTG
0
D5
C3VR[1]
0
D4
C3VR[0]
0
D3
C2VR[1]
0
D2
C2VR[0]
0
D1
C1VR[1]
0
D0
C1VR[0]
0
The extra volume resolution allows fine volume tuning by steps of 0.125dB.
The feature is enabled when VRESEN=1 , as depicted in Figure 31. The overall channel
volume in this case will be CxVol+CxVR (in dB). On top of the total volume range from
-80 dB to +48 dB, this extra volume resolution works in a volume range from -80 dB to +42
dB. For volumes greater than +42 dB, this function must not be selected.
Figure 31. Extra resolution volume scheme
CxVOL
Soft
Volume
MVOL or CxVOL’event
X
1
0
Audio Data In
0
Audio Data Out
X
1
VRESEN
VRESTG
CxVR
AM045196v1
If VRESEN = 0 the channel volume will be defined only by the CxVol registers.
Fine-tuning steps can be set according to the following table for channels 1, 2, 3:
CxVR
00
01
10
11
0 dB
-0.125dB
-0.25dB
-0.375dB
Mode
Doc ID 018572 Rev 3
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