At 08:32 AM 5/12/2004, Mike Rosing wrote: >On Wed, 12 May 2004, [iso-8859-1] Girish wrote:
>
> > Did you tried to implement direct form 2 IIR filter on
> > ADSP-2181 processor ?
With a fixed point dsp, especially 16 bit, you should use Direct Form I
Do a google search on this for deatils
>Nope.
>
> > Or do anyone know how to scale the coefficients ?
>
>With a simple multiply usually.
>
> > If yes, How did you solved the
> > problem of coefficients ?
>
>There's two ways. One is to get a book and learn the
>math. It's not hard, it just takes time. The second
>way is to get a program that does it for you. For
>example: http://www.icsi.berkeley.edu/~storn/fiwiz.html
>
A really good filter design program is QEDesign from Momentum Data Systems
www.mds.com
Al Clark
Danville Signal Processing, Inc.
--------------------------------
comp.dsp conference July 28 - Aug 1, 2004
Who says you can't teach an old dog a new DSP trick?
Reply by Mike Rosing●May 12, 20042004-05-12
On Wed, 12 May 2004, [iso-8859-1] Girish wrote:
> Did you tried to implement direct form 2 IIR
filter on
> ADSP-2181 processor ?
Nope.
> Or do anyone know how to scale the coefficients
?
With a simple multiply usually.
> If yes, How did you solved the
> problem of coefficients ?
There's two ways. One is to get a book and learn the
math. It's not hard, it just takes time. The second
way is to get a program that does it for you. For
example: http://www.icsi.berkeley.edu/~storn/fiwiz.html
Patience, persistence, truth,
Dr. mike
Reply by Girish●May 12, 20042004-05-12
hai all
Did you tried to implement direct form 2 IIR filter on
ADSP-2181 processor ?
Or do anyone know how to scale the coefficients ?
If yes, How did you solved the
problem of coefficients ?
see this filter wht i am trying to implement
Enter the pass band ripple...0.1
Enter the stop band ripple...40
Enter the pass band freq...1000
Enter the stop band freq...1100
enter the sampling frequency...8000
**************a coefficients*******************
Columns 1 through 4
Also in both of the coefficients "a and b" there are
18 coefficients , But the ADSP vol 1 book says
the elements should be 1 less in "a" array compared to
"b" array. But both are same here.
I read from one of the documents tht we need to
exclude 1.000000000(AD processor but some other
series). Also according the document the elements of
"a" should be negated and must be used in the reverse
order of appearance.
The same thing is true for "b" but there is no
negation.
I am little bit confused.
Plz help me out if possible.
Thanx for reply
Bye
G
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