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Altera_Forum's avatar
Altera_Forum
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17 years ago

what's wrong with my fft ipcore

I have instantiated a 256 points FFT, with single output and streaming architecture. The data width and twiddle factor precision is 16bits. I input the signals generated by matlab: n=0:2047; s...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

You are right. Matlab imaginary values are close to zero.

Your hardware results must be close to Matlab. So there is something wrong either in the IP core or the way you input your data.

imbalance of real/imag can easily occur in hardware even one sample lag leads to errors. One test is to use zero imag or zero real and then compare to matlab. A previous post used zero imag and their results were same as matlab apart from the scaling issue.