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AFE7900EVM: The multiple captured data lead to noisy heatmap

Part Number: AFE7900EVM
Other Parts Discussed in Thread: TSW14J57EVM

Good afternoon,

I have a AF7900 and TSW14J57EVM connected to each other. I capture the data with using HSDC Pro. 

I have a question about data from HSDC Pro. Data are noisy and I don't know what is the reason.

Now I want to explain you what I have done with using Automation DLL.

Here I read my first capture and save it

 

CaptureData_32bits = (c_ulonglong*Capture_Data_Array_Len)()
Err_Status = HSDC_Pro.Get_Capture_Data_32bits(Number_Of_Samples_Per_Channel,OffsetSamplePerChannel,CaptureData_32bits,Capture_Data_Array_Len,TimeoutinMs_Cap)
main_cap_array = (np.frombuffer(CaptureData_32bits, dtype = np.int32).reshape(Number_Of_Samples_Per_Channel*2,NoofChannels)[:][:Number_Of_Samples_Per_Channel] - 2**15)

Then I read the new capture again and stack it to the main array. I do it for 100 new captured data.

for i in tqdm(range(0,100)):
    Err_Status = HSDC_Pro.Pass_Capture_Event(Time_MS)
    if Err_Status !=0:
        print("Error is ", Err_Status)
    CaptureData_32bits = (c_ulonglong*Capture_Data_Array_Len)()
    Err_Status = HSDC_Pro.Get_Capture_Data_32bits(Number_Of_Samples_Per_Channel,OffsetSamplePerChannel,CaptureData_32bits,Capture_Data_Array_Len,Time_MS)
    if Err_Status !=0:
        print("Error is ", Err_Status)
    temp_cap_array = (np.frombuffer(CaptureData_32bits, dtype = np.int32).reshape(Number_Of_Samples_Per_Channel*2,NoofChannels)[:][:Number_Of_Samples_Per_Channel] - 2**15)
    main_cap_array = np.vstack((main_cap_array, temp_cap_array))

And finally, I save it as csv

fl = ("C:/Users/ferid/Desktop/gpr-data-python/1.csv").encode()
Err_Status = HSDC_Pro.Save_Raw_Data_As_CSV(fl,TimeoutinMs_Cap)

Everything works perfectly with Error Status as zero. However when I take the data and vertically plot it as heatmap, the data seems like too messy and noisy. I know it is not really continuos data, but it looks like the data sometimes too perfect and sometimes not. I don't know what the reason can be. I thought the reason can be that the HSDC Pro or TSW14J57EVM send the different data from different lane (RX) for each capture. Because from the picture you can see that in some cases the data is perfect and in another case it is not.

Thanks

  • Hi Farid,

    The issue that you are seeing may be occurring because of the TSW14J57EVM. When using the AFE79xxEVM and TSW14J57EVM together there are a couple of extra steps needed in order to consistently get good captures. 

    The extra steps required are given in the PowerPoint below. 

    AFE79xxEVM TSW14J57.pptx

    Regards,

    David Chaparro

  • Thanks for the quick response.

    It is better than before, but still it is not like I have wanted. The Fdac of the mode2 is 8847.36, and decimation for tx and rx is 18 and 12. I want my Fdac as 12G (11796.48M), and send and receive it with small decimation as much as I can. I change the Fdac to 11796.48 and use the decimation for that Tx (24), it works but I want to use small decimation as much as I can.

    From the configuration file I know that I can use maximum 1474.56M for tx (it is 8 decimation) and 737.28M for Rx (4 decimation) in single band. I change the Fdac and decimations of Tx and Rx according to the table at Configuration file, but it gives me the error. The Rx gives me Serdes range error, and Tx gives me the error of "Comma Align Lock Lane0: False; Please check if the transmitter is sending data and eye is good." I don't know it is because of the lmfshd, fpgaRefClk, FRef or any other parameters. I don't know I should change them as well or not. 

    Can I know which parameters I should change to use these decimations? If you will help me, I will be very glad, because for 1 months, I am trying to solve that configuration problem, and capturing the data I have desired.

  • Hi Farid,

    The issue that you are facing is most likely related to the lane rate limitation of the TSW14J57EVM. If you are using the LMFS mode 44210 and attempt to get a BW of 1474.56M the lane rate will be about 30Gbps which is higher than the capture card can handle. In order to achieve the BW that you are requesting you can switch to a 2T2R mode, 42220, and achieve a BW of 1474.56M with a lane rate of 14.7456Gbps, which can be supported on the TSW14J57. 

    I have created a script for the mode mentioned above where both Rx and Tx have a data rate of 1474.56M. I have also included the required ini files for HSDC Pro. 

    To use the new ADC ini file close HSDC Pro and copy the ini file to this location: C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro\14J57revE Details\ADC files

    To use the new DAC ini file copy the ini file to this location: C:\Program Files (x86)\Texas Instruments\High Speed Data Converter Pro\14J57revE Details\DAC files

    Please use the following link to download the script and ini files:

    https://tidrive.ext.ti.com/u/7lueTX3bnnL8W55K/2d29a81c-3540-4645-962b-f45745f70067?l 

    Regards,

    David Chaparro

  • Thank you so much. It solved my problem.