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- FFT length doesn't correspond to output? DSP builder

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Altera_Forum

Honored Contributor I

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07-03-2011
05:17 AM

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FFT length doesn't correspond to output? DSP builder

I'd really appreciate some help, I've been working at this for some time now,

I'm trying to verify my fft megafuntion in dspbuilder. I'm using a 64 point length streaming architecture, for the input just a sine wave source block. I've been plotting the results in matlab and what confuses me is the output frequency components don't repeat within my transform length. I would expect the output to be a stream of data each sample between my source sop and source eop, but in stead I See the data begin to repeat after maybe several or more sop - eop cycles. Can anyone tell me why? I know the output is dependent on the sampling frequency,is this my simulation clock? Thanks :DLink Copied

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Altera_Forum

Honored Contributor I

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07-03-2011
07:10 AM

26 Views

Altera_Forum

Honored Contributor I

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07-03-2011
11:34 PM

26 Views

Thanks Kaz,

that was my problem. This seems to restrict the frequencies I can transform. Is this a reason to use a different architecture/higher precision?For more complete information about compiler optimizations, see our Optimization Notice.