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RVanD5's avatar
RVanD5
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7 years ago

FFT Core - Variable streaming floating point - Arria 10. Output SOP and EOP are not aligned.

We are having trouble with the migration of the fixed point FFT core to the floating point FFT core on Arria 10. On example of strange behavior is seen in the the SignalTap below: the SOP en EOP mark...
RGroo3's avatar
RGroo3
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7 years ago

Hi,

We have the same issue with the FFT IP from Quartus17.1.

This issue does not occur in Quartus 16.1 (FFT IP version 16.1).

The issue occurs when the FFT IP is configured to 'Single Floating Point' and 'Enable Hard Floating Point Blocks' and Output Order set to 'Natural'. The issue does not occur with Output Order = 'Digit Reverse'.

The timing and behavior on the source output stream is exactly as desribed above in this case.