FPGA FFT Reset Required or No?

[AlexA]

Hey guys,

So, a quick question. Suppose I have the High-Throughput FFT in a single-cycle timed loop performing transforms on data-sets 1024 points long. For each set of 1024 points, which should be considered completely independent of each-other, do I need to trigger the reset line on the FFT?

I ask because I'm seeing a weird periodicity in the results of a "find max" type algorithm which is hunting through the magnitude of the frequency spectrum. At worst, the result of this "find max" should be random, not periodic in nature. My guess is that there is some sort of index shifting going on which could be a result of a bad indexing operation (something I can check and fix myself) or as a result of some sort of accumulation in the FFT.

Edit: A quick note, there is definitely no periodic shift in the data itself, it should be more or less constant.

Can anyone shed light on the matter?

Cheers,

Alex

Edited May 28, 2012 by AlexA