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Altera_Forum's avatar
Altera_Forum
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13 years ago

Strange FFT Output

I've been using SignalTap to create a CSV file of the output from my FFT engine. However, when looking at the output in Matlab, it doesn't look right at all. I know that the ADC's working prop...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

I have signaltapped the input, yes. However, I can't get to my Sig Gen and such until Monday to do any more tests. As for the sample rate, I'm clocking at 6.25kHz, which is my downsampled ADC output.

I may have cracked it now, although I don't wan't to get my hopes up too much as it's always just one thing after another... I think the problem might be coming when I write to file in my testbench, it's writing out as an unsigned decimal. By converting it to signed, it's actually starting to look right. Any ideas on how to get my testbench to write to file as a signed int rather than unsigned?