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Why did the filter parameter order change ?

Question asked by Beni on Mar 1, 2018
Latest reply on Jun 19, 2018 by Beni

Hi,

In SS 3.15 Build 2 Rev 1721 a new algorithm for the double precision filters is used.

I checked how this will affect the parameters and found that the order of the parameters in RAM has changed.

The  older version had the order A2 A1 B2 B1 B0.

The new version has the parameter order B2 B1 B0 A2 A1.

Now i have to maintain two methods for the parameter loading in my uC, far more worse is that old and new filters can  not be mixed in the design. This of course can not be handled properly.

Why did AD do this ? This seems not to make much sense.

If i want to add one filter to an existing old design, all old filters (up to several hundred) have to be changed. And of course the uC code has to be changed as well.

 

My questions are:

Is there a way to use/add old (obsolte) algorithms in a new design to maintain code compatibility?

How can i distinguish between the algorithms ?

Where can i access the old algorithm ?

What happens if old and new algorithms are mixed in one design (one dsp)?

 

Any suggestions appreciated

Best regards

Bernd

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