Note : I am using Linux version design . Not No-Os
Hi,Yes, it is correct. You might want to consider the upac/cpack cores if only one channel is enabled at a time.https://wiki.analog.com/resources/fpga/docs/hdl/fmcomms2_fir_filtAndrei
I integrated Xilinx FFT core in the path (util_ad9361_adc_fifo----->xfft(v.9)) . I am interested in data of dout_data_0 and dout_data_1.
1- For testing purpose I combined ( dout_valid_0 and dout_valid_1 ) and connected to s_axis_data_tvalid. of the fft core.
2- concatenated dout_data_0[15:0] and dout_data_1[15:0] and connected with s_axis_data_tdata[31:0] , connected
s_axis_tdata_tlast to a counter (that assert FFT_tlast if counter reaches to certain value ). and xfft clock is (aclk ---> din_clk )
3- m_axis_data_tdata[31:0] -----> ILA(probe 31:0) ,
m_axis_status_tdata[7:0] ----> probe 7:0 ,
m_axis_data_tuser[23:0] ---> probe ,
m_axis_data_tvalid ----> probe ,
event_tlast_unexpected ----> probe ,
event_tlast_missing ----> probe ,
event_data_in_channel_halt ----> probe
4- after connecting equipment ( signal generator ----> RX1A) and I got the attached result.
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.
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
Hi,Change your signal to 137MHz (LO + sine). But I don't think you will get a valid result with this approach. You need a proper modulated sine wave.What type FIFO(adc_fifo) have you connected there, and can you give more details about its connections?
travisfcollins can you comment on this?Andrei
Based on your configuration your tone should appear at -1MHz. If you are not FFT shifting the output it may appear at FS/2 -1MHz.
Dear andrei_g & travisfcollins
Thank you for your valuable suggestion .i performed some task . sent the captured data to MATLAB and checked the frequency on Simulink Spectrum Analyzer.
Settings were following
ADC FIFO(ADI version 2018_r1) = 100Mhz
Simulink Spectrum analyzer sampling frequency = 100 Mhz
RF IN (RX1A) = maximum Peak
My understanding from your suggestion that if Lo=155 RFin=156 the peak shall be at 1 , and so (RFin-LO) . but as evident from the above table the difference is increasing by factor more or equal to 1.6 factor . Kindly your views on this .
Hi,Can you post here the whole interface between axi_ad9361 and adc_fifo?Andrei
The interface snap is attached.
At this stage, I have not changed the reference design but added my logic. Here is the summary of my logic.
I concatenated the ADC FIFO's dout_data0 and dout_data1 (considering dout_data0 as real part (I data) and dout_data1 as imaginary part (Q data)). This data goes to FFT IP core (Xilinx xfft 9.0). Enable and valid signals are also connected to respective FFT core inputs. The output of FFT core is connected to ILA and MATLAB data capture IP (shown as RTL block in my design) .
My logic part is synchronized with dout_clk of ADC_FIFO (100Mhz).
I'm avoiding to post the whole design as it's a public space. I can privately send you that if u want.