FFT in FPGA?

[walker1]

Not quite sure where to put this.

I just had a request yesterday, if I would be able to create a small, say 4, 12 bit inputs, FFT in a FPGA.

We use the Altera Cyclone series, and Altera does have a MegaCore FFT, which, however, starts at 64 inputs and uses way too many resources in the Cyclone. A posting to Altera's support has revealed, that the function can not be scaled down.

In other words, I have to create something myself.

Does anybody know where to find an algorithm, that can be implemmented without using a DSP core or similar?
I do have a Pascal module I can try to figure out, but if it is of any use for hardware is unknown.

 

[NWBeaver]

Walker,
You probably need to post this question in the Circuits Engineering forum, (forum240).

http://www.eng-tips.com/threadminder.cfm?pid=240

 

[nbucska]

What is the required speed? How many units do you need ?
( wouldn't be possible/worth to use a microcontroller or DSP?)

<nbucska@pc33peripherals.com> omit 33 Use subj: ENG-TIPS
Plesae read FAQ240-1032

 

[walker1]

nbucska
I followed NWBeaver's advice and posted more or less the same question under Circuit Engineering.

The answers there were more like questions to what on Earth I was trying to do, so I put a much more detailed description about the system there.

Also, I have now tried to simulate the system i Exel, which shows that it seems to work. Don't ask me too much about WHY.
Our math guys are stil debating that part.