Forum Discussion

RVanD5's avatar
RVanD5
Icon for New Contributor rankNew Contributor
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...
RVanD5's avatar
RVanD5
Icon for New Contributor rankNew Contributor
7 years ago

Hi,

Well, basically, there is only a single issue: the FFT does not output pending data on its source when a valid eop has been

registered on its sink I our preliminary hypothesis.

I tested it with 2 x 4096 consecutive streans, and it shows the same behavior. Only in this case only a single output word

is omitted. The EOP is asserted for the second stream, but the valid has already be deasserted.

And an overview:

I have not looked at the generated tb yet. Can you confirm that we have understood correctly that the FFT core

should present all data pending in the pipeline after the EOP on sink, independent of the valid state of the sink after

the EOP?

Regards,

Rob