sta381bw STMicroelectronics, sta381bw Datasheet - Page 144

• Manufacturer Part Number: sta381bw
• Description: Sound Terminal 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

Register description: Sound Terminal compatibility
7.17
Note:
144/168
EQ soft volume configuration registers (addr 0x37 - 0x38)
The soft volume update has a fixed rate by default. Using register 0x37 and 0x38 it is
possible to override the default behavior, allowing different volume change rates.
It is also possible to independently define the fade-in (volume is increased) and fade-out
(volume is decreased) rates according to the desired behavior.
Table 160. Soft volume update enable, increase
When SVUPE = 1 the fade-in rate is defined by the SVUP[4:0] bits according to the following
formula:
where N is the SVUP[4:0] value.
Table 161. Soft volume update enable, decrease
When SVDWE = 1 the fade-out rate is defined by the SVDW[4:0] bits according to the
following formula:
where N is the SVDW[4:0] value.
For fade-out rates greater than 6 dB/msec it is suggested to disable the CPWMEN bit and
ZCE bit in order to avoid any audible pop noise.
Reserved
Reserved
D7
D7
Fade-in rate = 48 / (N + 1) dB/ms
Fade-in rate = 48 / (N + 1) dB/ms
0
0
SVDWE
SVUPE
0
1
0
1
Reserved
Reserved
D6
D6
0
0
SVDWE
SVUPE
When volume is increased, use the default rate
When volume is increased, use the rates defined by SVUP[4:0].
When volume is decreased, use the default rate
When volume is decreased, use the rates defined by SVDW[4:0].
D5
D5
0
0
Doc ID 018835 Rev 2
SVUP[4]
SVDW4]
D4
D4
0
0
SVDW[3]
SVUP[3]
D3
D3
0
0
Mode
Mode
SVDW[2]
SVUP[2]
D2
D2
0
0
SVDW[1]
SVUP[1]
D1
D1
0
0
STA381BW
SVDW[0]
SVUP[0]
D0
D0
0
0