[USRP-users] How do I change the number of taps and tap coefficients for the noc_block_fir_filter?

Martin Braun martin.braun at ettus.com
Thu Mar 24 19:24:38 EDT 2016


Our C++ block controller code actually pads taps with zeros. So it would
work in this case.

Cheers,
Martin

On 03/23/2016 07:55 PM, Jonathon Pendlum wrote:
> Hi Craig,
> 
> At first you would see no difference as only 21 coefficients would be
> loaded but the block expects 41. If you sent your 21 coefficients again,
> then your filter output would look distorted as the second set of
> coefficients would complete the expected 41. Basically, don't do this. :-)
> 
> 
> 
> Jonathon
> 
> On Wed, Mar 23, 2016 at 7:47 PM, Swanson, Craig
> <Craig.Swanson at gtri.gatech.edu <mailto:Craig.Swanson at gtri.gatech.edu>>
> wrote:
> 
>     Jonathon,____
> 
>     Yes, I modified the axi_fir.xci file to have 41 coefficients.  So I
>     just wanted to verify the scenario if the .bit file specified 41
>     coefficients and the python file generated in GRC specified 21, what
>     would happen?____
> 
>     __ __
> 
>     Craig____
> 
>     __ __
> 
>     *Craig F. Swanson____*
> 
>     *Research Engineer II____*
> 
>     *Information and Communications Laboratory____*
> 
>     *Communications, Systems, and Spectrum Division____*
> 
>     Georgia Tech Research Institute____
> 
>     Room 560____
> 
>     250 14^th Street NW____
> 
>     Atlanta, GA 30318____
> 
>     Cell: 770-298-9156 <tel:770-298-9156>____
> 
>     http://www.gtri.gatech.edu____
> 
>     __ __
> 
>     *From:*Jonathon Pendlum [mailto:jonathon.pendlum at ettus.com
>     <mailto:jonathon.pendlum at ettus.com>]
>     *Sent:* Wednesday, March 23, 2016 10:36 PM
>     *To:* Swanson, Craig <Craig.Swanson at gtri.gatech.edu
>     <mailto:Craig.Swanson at gtri.gatech.edu>>
>     *Cc:* usrp-users at lists.ettus.com <mailto:usrp-users at lists.ettus.com>
>     *Subject:* Re: How do I change the number of taps and tap
>     coefficients for the noc_block_fir_filter?____
> 
>     __ __
> 
>     I think you figured this out (per another thread you posted) but in
>     case you didn't, you need to generate a new .xci file for the AXI
>     FIR filter. You can use the Vivado GUI to do that.____
> 
>     __ __
> 
>     __ __
> 
>     __ __
> 
>     Jonathon____
> 
>     __ __
> 
>     On Wed, Mar 23, 2016 at 1:47 PM, Swanson, Craig
>     <Craig.Swanson at gtri.gatech.edu
>     <mailto:Craig.Swanson at gtri.gatech.edu>> wrote:____
> 
>         ​Jonathon,____
> 
>         I remember you reviewed how to do this at GRCon15, but I don't
>         remember.____
> 
>         Craig____
> 
>         __ __
> 
>         *Craig F. Swanson*____
> 
>         */Research Engineer II/*____
> 
>         */Information and Communications Laboratory/*____
> 
>         */Communications, Systems, and Spectrum Division/*____
> 
>         /Georgia Tech Research Institute/____
> 
>         /Room 560
>         250 14th St NW/____
> 
>         /Atlanta, GA 30318/____
> 
>         /Cell: 770.298.9156 <tel:770.298.9156>/____
> 
>         http://www.gtri.gatech.edu
>         <https://mail.gtri.gatech.edu/owa/redir.aspx?C=c20925f2f0af4dd29329ddf0701ecfff&URL=http%3a%2f%2fwww.gtri.gatech.edu%2f> ____
> 
>         __ __
> 
>     __ __
> 
> 





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