XADC AND XFFT

[ayhan]

I am tryna take the fft of the data that is coming out from xadc but there is a huge problem in my fft output and dont know why. I am giving 30k Hz sine wave input to my xADC then making them oversample.After this,I am sending the output to the bram.There is an another module between xfft and BRAM to handle the handshaking.Then taking the fft using xfft ip block.My ILA output is shown below.The top output is BRAM output,the middle one fft output and the bottom is ADC output.I think there is no any problem with my adc block. The problem is starting after XADC block but i couldnt find what problem is this.Can someone help me to figure this out ?

My design is running at 100mHz. The analog input is 40kHz sine wave that is provided from signal generator.

 

 

Edited April 1, 2022 by ayhan
syntax

[ayhan]

This is my final output.I think I can get fft but there is too much noise in the output.I can see two peaks both negative and positive sides in the output.How can i get rid of this noise  ?

[Richm]

You need to filter, window and possibly zero-pad the input to the FFT.

Streaming raw data into an FFT results in what you got.

[ayhan]

On 4/2/2022 at 10:48 PM, Richm said:

You need to filter, window and possibly zero-pad the input to the FFT.

Streaming raw data into an FFT results in what you got.

Thank you for your suggestions sir. I will try to make your suggestions. If I still encounter this problem i will update this post :)