Sign in

username:

password:



Not a member?

Search c54x



Search tips

Subscribe to c54x



c54x by Keywords

5409 | 5416 | AD5 | ADC | BIOS | Boot | Booting | Bootloader | C540 | C5402 | C5409 | C5416 | CCS | Codec | DMA | Dmad | DSK | DSKPlus | Dsplib | EVM | FFT | FIR | Flash | GPIO | HPI | Initialization | Interrupt | JTAG | LOG_printf | MCBSP | RFFT | RTDX | Sampling | STLM | UART | VC540

Ads

Discussion Groups

Discussion Groups | TMS320C54x | convert direct form filters to SOS DF2 form

Technical discussions about the TI C54x DSPs (including the c5401, c5402, c5402a, c5404, c5407, c5409, c5409a, c5410, c5410a, c5416, c5420, c5421, c5441, c549, c5470 and c5471).

  

Post a new Thread

convert direct form filters to SOS DF2 form - megha daga - Aug 28 10:21:02 2007



Hi Everyone,

I know that MATLAB can convert direct form filters to biquads/SOS DF2 form. I wanted to know if
there are any other softwares which can do that. 

Kindly let me know if anyone knows about any other software.

Thanking You
Megha
       
---------------------------------
Yahoo! oneSearch: Finally,  mobile search that gives answers, not web links. 


(You need to be a member of c54x -- send a blank email to c54x-subscribe@yahoogroups.com )

Re: convert direct form filters to SOS DF2 form - Jeff Brower - Aug 28 12:12:45 2007

Megha-

> I know that MATLAB can convert direct form filters to biquads/SOS DF2 form.
> I wanted to know if there are any other softwares which can do that. 
>
> Kindly let me know if anyone knows about any other software.

If the MATLAB function to which you are referring is given only arbitrary
coefficients, and knows nothing about the original design method, then it's
performing factoring to find the 2nd order sections.  If that's what you want, then
you can search for software that is capable of factoring, finding roots/zeros, etc.

But it may not be what you want.  In your application, do you know the original
design method and filter parameters?  If so, then you can "back up one step" to find
the 2nd order sections.

-Jeff



(You need to be a member of c54x -- send a blank email to c54x-subscribe@yahoogroups.com )

Re: convert direct form filters to SOS DF2 form - megha daga - Aug 29 8:11:56 2007

Hi Jeff,
   
  Thanks fo rthe reply.
  I am calculating the direct form filters using MATLAB (cheby2). So now I have Num and Den for
the IIR filter and I want to find the biquads. I am using "tf2sos" to get biquads. I
want to use some other software to confirm these.
   
  Thanks,
  Megha

Jeff Brower <j...@signalogic.com> wrote:
          Megha-

> I know that MATLAB can convert direct form filters to biquads/SOS DF2 form.
> I wanted to know if there are any other softwares which can do that. 
>
> Kindly let me know if anyone knows about any other software.

If the MATLAB function to which you are referring is given only arbitrary
coefficients, and knows nothing about the original design method, then it's
performing factoring to find the 2nd order sections. If that's what you want, then
you can search for software that is capable of factoring, finding roots/zeros, etc.

But it may not be what you want. In your application, do you know the original
design method and filter parameters? If so, then you can "back up one step" to find
the 2nd order sections.

-Jeff



(You need to be a member of c54x -- send a blank email to c54x-subscribe@yahoogroups.com )

Re: convert direct form filters to SOS DF2 form - Jeff Brower - Aug 29 12:56:00 2007

Megha-

>   Thanks fo rthe reply.
>   I am calculating the direct form filters using MATLAB (cheby2). So now I have Num and
Den for the IIR filter and I
> want to find the biquads. I am using "tf2sos" to get biquads. I want to use some
other software to confirm these.

Well, you could use other filter design software to design an identical Chebyshev II filter and
compare the biquads
that come out of it.  I searched "online filter design" in Google and several sites
came up that look promising.

Also, if you give me your filter specs, I'll put them in to Hypersignal software and give you
back the filter
coefficient file (which has num and den in 2nd order section format).

-Jeff

> Jeff Brower <j...@signalogic.com> wrote:
>           Megha-
>
>> I know that MATLAB can convert direct form filters to biquads/SOS DF2 form.
>> I wanted to know if there are any other softwares which can do that.
>>
>> Kindly let me know if anyone knows about any other software.
>
> If the MATLAB function to which you are referring is given only arbitrary
> coefficients, and knows nothing about the original design method, then it's
> performing factoring to find the 2nd order sections. If that's what you want, then
> you can search for software that is capable of factoring, finding roots/zeros, etc.
>
> But it may not be what you want. In your application, do you know the original
> design method and filter parameters? If so, then you can "back up one step" to
find
> the 2nd order sections.
>
> -Jeff



(You need to be a member of c54x -- send a blank email to c54x-subscribe@yahoogroups.com )