BU9408KS2_12 Datasheet, PDF (22/57 Pages) Rohm – 32bit Audio DSP with Built-in 4ch DAC and ASRC

BU9408KS2
Technical Note
○Pulse sound detection and High-speed recovery function（functioning only at the time of transition of (2)<->(3)）
P²Volume function makes the P²Volume also compatible with large pulse sounds (clapping of hands, fireworks & shooting
etc.) in addition to normal P²Volume operation. When large pulse sound is inputted, attack operation (A_RATE) or recovery
operation (R_RATE) is performed at 4 or 8 times the speed of normal attack operation or recovery operation.
Selection of using the pulse sound detection function.
Default = 0
Select Address
&h3BC [ 7 ]
Value
0
1
Operational explanation
Not using of pulse sound detection function
Using of pulse sound detection function
Selection of operating times of Recovery Time (R_RATE) in the case of using the pulse sound detection function
Default = 0
Select Address
&h3C [ 3 ]
Value
0
1
Operational explanation
Operating at 4 times the speed corresponding to the setting time of
R_RATE
Operating at 8 times the speed corresponding to the setting time of
R_RATE
Selection of pulse sound detection time
Default = 0
Select Address
&h3C [ 6:4 ]
Operational explanation
Command
0
1
2
3
Detection time
100us
200us
400us
1ms
Command
4
5
6
7
Detection time
2ms
5ms
10ms
20ms
Setting of operating level of pulse sound detection function
Operation is started by the difference between the presently detected value and the last value as a standard.
Default = 0
Select Address
&h3C [ 2:0 ]
Operational explanation
Command Detection level Command
0
Over 1.002
4
1
Over 0.709
5
2
Over 0.502
6
3
Over 0.355
7
Detection level
Over 0.251
Over 0.178
Over 0.126
Over 0.089
Example） Present detection level A ： -10dB → 10^(-10/20) = 0.32
The last detection level B ： -30dB → 10^(-30/20) = 0.032
A – B : 0.32 – 0.032 = 0.288 → Operating by the setting of command ”4” to ”7”.
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22/53
2012.03 - Rev.A