BU9414FV Datasheet, PDF (34/61 Pages) Rohm – 32bit Audio DSP

BU9414FV
Technical Note
4-12. Scaler
Scaler adjusts the gain in order to prevent the overflow in DSP.
Adjustable range is +24dB to -103dB and can be set by the step of 0.5dB.
Scaler 1 does not incorporate the smooth transition function.
Default = 30h
Select Address
&h24 [ 7：0 ]
Operational explanation
Command
00
01
Gain
+24dB
+23.5dB
30
0dB
31
-0.5dB
32
-1dB
FE
-103dB
FF
-∞
4-13. 7 band・parametric equalizer
7-band parametric equalizer can use Peaking filter, Low-shelf filter or high-shelf filter.
The setting is converted, in the IC, into digital filter’s coefficients （b0, b1, b2, a1, a2）by selecting the F，Q and Gain, and
transmitted to coefficient RAM. There is no smooth transition function.
Band1 Band2 Band3 Band4 Band5 Band6 Band7
Level
±18dB
f
(0.5dB step)
63
160
400
1k
2.5k
6.3k
16k
(Hz)
Selection of filter types
Default = 0
Select Address
bit[ 7:6 ]
It sets to all band
Value
0
1
2
Peaking filter
Low-shelf filter
High-shelf filter
Operational explanation
Setting of the Start of transmitting to coefficient RAM
It is transmitted to direct coefficient RAM.
Default = 0
Select Address
bit [ 0 ]
It sets to all band
Value
0
1
Operational explanation
Coefficient transmission stop
Coefficient transmission start
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2012.03 - Rev.A