01-06-2014 07:24 AM
Take standart FFT core (FFT8 or 9) and and configure it the following parameters:
1024 tr length;
12 bit data and 20 width phase factor;
non real time.
Further test the core is attached testbench which contain real data from adc and different config_tdata (FFT_TestB.v)
And as a result we get a weird output data:
m_axis_data_tdata_re and m_axis_data_tdata_im.
01-06-2014 11:59 AM - edited 01-06-2014 05:30 PM
The core is telling you that your tlast has a problem (missing & unexpected tlast). Your problem is that tlast should indicate that the current tvalid is the last one, ie it should overlap the tvalid which validates the last valid data. Your tlast has no associated tvalid (so unexpected tlast) and the end of your frame does not have a tlast (missing tlast).
01-06-2014 11:39 PM
01-06-2014 11:47 PM
01-07-2014 11:22 PM
q- you seem to be reconfiguring the fft every frame. is this really what you want ?
a- I just tested in various configurations to see which one is the correct configurations, like in demo testbench.
q- also do you give the fft enough time to accept the new configuration?
a- certainly enough time, look at the signal m_axis_data_tvalid.
01-08-2014 08:19 AM
01-08-2014 08:48 AM