12-14-2016 10:55 AM
Please i want to ask very important thing and i really need a help . I have been trying to debug the FFT core v9.0 on vivado since two months approximately , but i'm still stuck with it . The FFT core gives me nothing at the output , it's just gives a peaks on the first and the last points of the frame (0.N-1) , but in other points i have nothing , it looks like there is no frequency in my input signal or something like that !
The picture below shows the results that i'm getting from each XADC and the FFT core , i'm really stuck here i couldn't understand what's the exact problem or what's wrong here so i can fix it to make the core works .
The sampling frequency of my XADC is about 1MSPS while i tried all possible frequencies for the input signal starts from 10 Khz up to 480 Khz which is the maximum freq i can use , FFT points are 1024 and i tried both scaled and unscaled design , and its in real time mode with natural order output . And the results are same for all cases above .
Please if anyone knows the problem and what's going on here i would really appreciate the help .
Note that this is not a simulation results , it's a really results taken by the ILA debugging core .
12-14-2016 11:44 AM
@mohamed.shfat your description of your problem is not very clear. Can you capture the XADC output and run FFT on it and compare the results with a simulation of your logic and or the ILA captured data? It seems your waveform is zoomed-out. You can zoom in and see what values you have other than the peaks. Also how do you compute the magnitude of the FFT output ? Verify you are computing it correctly.
12-14-2016 11:00 PM
12-15-2016 08:01 AM
@mohamed.shfat You should data you capture from XADC and simulate it with your design. It's difficult to debug why hardware is not working if you don't have a working simulation. After you have a working simulation, you can check the input/output handshake signalling of the FFT block to see if it is behaving the same way.