Re: [casper] 32 Channel PFB and Wideband Real FFT . . .

2016-07-18 Thread G Jones
Hi Randy,
I think the issue is that you are processing 16 samples per FPGA clock for
VEGAS (if I remember right), so I expect you'll need to hand craft an FFT
out of the FFT direct block and twiddle blocks. It might be easier to use a
xilinx block in this case, but I haven't actually looked at what's
available.
Glenn

On Mon, Jul 18, 2016 at 1:04 PM, Randy McCullough  wrote:

> All,
>
> We're currently in the process of adding incoherent and coherent
> de-dispersion
> pulsar modes to our ROACH 2-based VEGAS backend and have hit a stumbling
> block.  We've built all designs ranging from 8,192 channels down to 64
> channels,
> but when attempting to implement a 32-channel design the standard Wideband
> Real FFT block breaks.  Has anyone successfully implemented a 32 channel
> PFB/FFT
> pair on a ROACH 2 platform?
>
> Randy
>
>


[casper] 32 Channel PFB and Wideband Real FFT . . .

2016-07-18 Thread Randy McCullough

All,

We're currently in the process of adding incoherent and coherent 
de-dispersion

pulsar modes to our ROACH 2-based VEGAS backend and have hit a stumbling
block.  We've built all designs ranging from 8,192 channels down to 64 
channels,

but when attempting to implement a 32-channel design the standard Wideband
Real FFT block breaks.  Has anyone successfully implemented a 32 channel 
PFB/FFT

pair on a ROACH 2 platform?

Randy