FFT Source_valid

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after transfering some data packages, the sink_valid kept high, no sink/source_errors, the core should assert the "source_valid" high - but it isn't.

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why do you say there are no errors? it clearly shows source_error=1 which means missing sop. Recheck you sop eop, they should be one clock long and correctly spaced. To improve your test validity you should really put some data !=0. DC or just put random pattern.

Edit:[Be aware that the very first input sample having sink_valid=1, sink_ready=1 MUST also have SOP=1, otherwise you get missing sop]