Inserting FFT core for verification of Rx path using HDL linux SW

I am working on ADRV9361-z7035 with HDL release (2018_r1) . And I am using Linux version .
I want to verify the RX path . by injecting a RF signal of a particular frequency on RX port.bring received signal to 
FFT core , and processing it . and verify the frequency component (using ILA ) .

So for my understing from the forum threads is

recommended place to put FFT IP is AD9361 Interface ---> FIFO ---> FFT IP ----> DMA controller ---> Interconnect back to PS.
So it is the correct dataflow to implement FFT core.

Note : I am using Linux version design . Not No-Os



Parents Reply
  • need your guidance in interpreting the FFT result .  the snap is attached . 

    1- For confirmation of FFT core setting , I checked by generating a signal from DDS core and injecting into FFT core and I got the correct index number by using the formula ( index number (on which peak detected ) X Fs/N where Fs is sampling frequency and  N FFT points . so my FFT core setting is correct .

    2- Now after inserting FFT core  in Rx data path (util_ad9361_adc_fifo----->xfft(v.9)) . I got the result (snap is attached ) . and applied signal is 135Mhz on RX1A and LO (setting by IIO Oscilloscope Rx LO=136) . and FFT core is running is on 100Mhz clock rate(adc_fifo output rate ). Using the above formula and LO , I tried to calculate the right index for the FFT of applied signal but that doesn't seems correct. (Image attached).

    Can u please check this and suggest me if this approach is correct. if not, please guide me to find the correct index   ? .and what would be suggested waveform of tdata?????

    ALL the snaps and ILA data is attached for reference.fifo_out.xlsxFFT_output.xlsx

    FFT of 1Mhz Signal applied through DDS, checked on ILA. Got correct results.

    FFT of 1Mhz signal applied through DDS

    ADC fifo output before packing of data. 

    Data path of the overall design, Reference design is not modified but another core is added like shown in this figure