BD9406KS2 Datasheet, PDF (24/38 Pages) Rohm – 28bit Audio DSP with Built-in 2ch ADC, 6ch DAC and ASRC

BU9406KS2
Technical Note
4-8-1. Parametric EQ Coefficient Configuration Method
① Set &h40[7] to “L”.
② Configure the address (7bits) of the coefficient number to be converted at &h41[6:0].
Configure the data (24bits) at &h42[7:0], &h43[7:0] and &h44[7:0].
③ Set &h40[7] to “H”. Data can be collectively written into the coefficient RAM of the appointed coefficient numbers.
④ The write-in to the coefficient RAM completes when &h46[6] is read out and confirmed to be “L”, or after a 20µs wait.
Afterwards, set &h40[7] to “L”.
⑤ With coefficients, h7FFFFF (maximum value) refers to +4-1LSB and h800000 (minimum value) refers to -4. In addition,
h200000 refers to +1, h00000 refers to 0, and hE00000 refers to -1.
4-8-2. Soft Transition Usage Method During Coefficient Switching of Parametric EQ
① Configure the transition time at &h45[5:4].
② New coefficients are set to the transition filters of two channels. To transit the first 5 bands (same coefficients for both
channels), the same coefficients must be set to the transition filters of both channels.
③ Set the filter number to transit at &h45[3:0]. Transition begins.
④ seni_busy (signal read out at &h46[7]) becomes “H”, and turns to “L” when transition is complete.
⑤ 0 must be set to &h45[3:0] when transition is complete, finishing the soft transition operation.
4-9. EVR (Electrical Volume) and Balance
The volume can be selected in 0.5dB increments from +24dB to -103dB.
Soft transition is performed when volume is changed. It takes approximately 21ms to go from 0dB to mute.
The balance can be decreased in 1dB increments from the volume configuration value. Soft transition is performed at
switch.
Volume Configuration
Default = 00h
Select Address
&h24 [ 7：0 ]
Operation Description
L/R Balance Configuration
Default = 80h
Select Address
&h25 [ 7：0 ]
Operation Description
Balance Configuration
Command Value Lch
00
0dB
01
0dB
Rch
-∞
-126dB
7E
0dB -1dB
7F
0dB 0dB
80
0dB 0dB
81
-1dB 0dB
FE
-126dB 0dB
FF
-∞
0dB
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2012.03 - Rev.A