Re: [casper] Weird FFT Output

[Amit Bansod]

Hi Jack,

I finally got hold of this issue.

The problem was in the pfb_fir_generic block. After replacing it, the
fft output was as expected.


Cheers,
Amit

On 06-Nov-15 5:04 PM, Jack Hickish wrote:
> Hi Amit,
> 
> I've hastily fixed that error regarding bram latency -- it's pushed to
> the master casper branch at https://github.com/casper-astro/mlib_devel.git
> 
> You should be able to cherry pick that commit into your repository, but
> I recommend just using the casper-astro master branch rather than the
> SMA branch you're currently working with. The SMA code was merged into
> casper-astro more recently than the commit you are currently at anyway.
> 
> As for your spectra, I'd suggest seeing if the problem persists with the
> latest casper-astro master branch and then investigating further from there.
> 
> Cheers,
> Jack
> 
> 
> On Fri, 6 Nov 2015 at 11:14 Amit Bansod  > wrote:
> 
> Dear All,
> 
> I am trying to extract 1 channel/band using PFB/FFT (pfb_fir_generic &
> fft_wideband_real blocks from casper library) and I am getting
> inconsistent result from a 64 channel PFB/FFT.
> 
> I also found that the for 64 channel FFT, the fft_wideband_real block
> breaks at fft_wideband_real/fft_biplex_real_4x/bi_real_unscr_4x/delay0
> (or ../bi_real_unscr_4x/delay1) for BRAM latency > 2. Can this be also a
> cause for concern ?
> 
> I have enclosed the plots of the same band for the 64 & 128 channel
> FFTs. The BW of 1 band is 12.5 MHz for 128 channels and 25 MHz for 64
> channels FFT.
> 
> The design has ASIAA 5g ADCs with fpga running at 200 MHz and same noise
> source is feeding both ADCs.
> 
> I am using the sma-wideband repository with commit : ecab6f5
> 
> 
> Regards,
> Amit Bansod
> 

Re: [casper] Weird FFT Output

[Andrew Martens]

Hi Amit

We have also identified a bug in the pfb_fir_generic block and are working
on debugging it. Will let you know when we have a solution. Sorry for the
inconvenience.

Regards
Andrew

On Thu, Jan 21, 2016 at 11:18 AM, Amit Bansod 
wrote:

> Hi Jack,
>
> I finally got hold of this issue.
>
> The problem was in the pfb_fir_generic block. After replacing it, the
> fft output was as expected.
>
>
> Cheers,
> Amit
>
> On 06-Nov-15 5:04 PM, Jack Hickish wrote:
> > Hi Amit,
> >
> > I've hastily fixed that error regarding bram latency -- it's pushed to
> > the master casper branch at
> https://github.com/casper-astro/mlib_devel.git
> >
> > You should be able to cherry pick that commit into your repository, but
> > I recommend just using the casper-astro master branch rather than the
> > SMA branch you're currently working with. The SMA code was merged into
> > casper-astro more recently than the commit you are currently at anyway.
> >
> > As for your spectra, I'd suggest seeing if the problem persists with the
> > latest casper-astro master branch and then investigating further from
> there.
> >
> > Cheers,
> > Jack
> >
> >
> > On Fri, 6 Nov 2015 at 11:14 Amit Bansod  > > wrote:
> >
> > Dear All,
> >
> > I am trying to extract 1 channel/band using PFB/FFT (pfb_fir_generic
> &
> > fft_wideband_real blocks from casper library) and I am getting
> > inconsistent result from a 64 channel PFB/FFT.
> >
> > I also found that the for 64 channel FFT, the fft_wideband_real block
> > breaks at
> fft_wideband_real/fft_biplex_real_4x/bi_real_unscr_4x/delay0
> > (or ../bi_real_unscr_4x/delay1) for BRAM latency > 2. Can this be
> also a
> > cause for concern ?
> >
> > I have enclosed the plots of the same band for the 64 & 128 channel
> > FFTs. The BW of 1 band is 12.5 MHz for 128 channels and 25 MHz for 64
> > channels FFT.
> >
> > The design has ASIAA 5g ADCs with fpga running at 200 MHz and same
> noise
> > source is feeding both ADCs.
> >
> > I am using the sma-wideband repository with commit : ecab6f5
> >
> >
> > Regards,
> > Amit Bansod
> >
>
>

Re: [casper] Weird FFT Output

[Jack Hickish]

Hi Amit,

I've hastily fixed that error regarding bram latency -- it's pushed to the
master casper branch at https://github.com/casper-astro/mlib_devel.git

You should be able to cherry pick that commit into your repository, but I
recommend just using the casper-astro master branch rather than the SMA
branch you're currently working with. The SMA code was merged into
casper-astro more recently than the commit you are currently at anyway.

As for your spectra, I'd suggest seeing if the problem persists with the
latest casper-astro master branch and then investigating further from there.

Cheers,
Jack


On Fri, 6 Nov 2015 at 11:14 Amit Bansod  wrote:

> Dear All,
>
> I am trying to extract 1 channel/band using PFB/FFT (pfb_fir_generic &
> fft_wideband_real blocks from casper library) and I am getting
> inconsistent result from a 64 channel PFB/FFT.
>
> I also found that the for 64 channel FFT, the fft_wideband_real block
> breaks at fft_wideband_real/fft_biplex_real_4x/bi_real_unscr_4x/delay0
> (or ../bi_real_unscr_4x/delay1) for BRAM latency > 2. Can this be also a
> cause for concern ?
>
> I have enclosed the plots of the same band for the 64 & 128 channel
> FFTs. The BW of 1 band is 12.5 MHz for 128 channels and 25 MHz for 64
> channels FFT.
>
> The design has ASIAA 5g ADCs with fpga running at 200 MHz and same noise
> source is feeding both ADCs.
>
> I am using the sma-wideband repository with commit : ecab6f5
>
>
> Regards,
> Amit Bansod
>