5 TX to FB Loopback With DDR Example

Steps:

1. Make sure that the SMA cables are connected so that the first two TX RF ports (TX1-TX2) are connected to the two FB RF ports (FB1-FB2, respectively).
2. Copy your waveform file from the host pc to the Arm node using the command scp <path to the waveform file> root@192.168.0.1:/home/root/jesd_tools/data/ in PowerShell. For the setup, the command scp .\jesd\TM3.1a_FDD_737.28MHz_eSOM_ACLRver.txt root@192.168.0.1:/home/root/jesd_tools/data/ was used.
   1. The format of the waveform file is such that each sample occupies a line with a 16-bit hex value for the I portion in the first column and a 16-bit hex value for the Q portion in the second column.
3. On the Arm node (Teraterm), run the command below to simultaneously playback the samples of the waveform to each of the first two TX channels channels from the FPGA and capture the samples from each of the two FB channels in 4T4R2F mode.
   1. run_jesd_cw_lpbk_tests_with_ddr.sh -s=8 -n=2 -f=jesd_tools/data/TM3.1a_FDD_737.28MHz_eSOM_ACLRver.txt
   2. The expected output is shown in Figure 5-1.
   Figure 5-1 Expected Output After Running the Loop-Back Command
4. At the end of the execution, there should be two capture files created with names of cw_capture_fb[0-1].txt in jesd_tools/log folder on the Arm node. Copy one of them to the host PC in the Hitek_RF_INTF_Common_Files_2023-06-07\software\x64_64\analysis\jesd folder using the command scp root@192.168.0.1:/home/root/jesd_tools/log/cw_capture_fb0.txt <location to copy>. In our setup the command, scp root@192.168.0.1:/home/root/jesd_tools/log/cw_capture_fb0.txt jesd/ was used.
5. Run the .\run_freq_plot.exe 2 .\\cw_capture_fb0.txt 737280000 command from the Hitek_RF_INTF_Common_Files_2023-06-07\software\x64_64\analysis\jesd directory to display a Fast Fourier Transform (FFT) with Hamming window of the FB capture. The FB is sampled at 737.28Msps in 4T4R2F mode and is shown in Figure 5-2. You can zoom in to adjust the view in the image.
   Figure 5-2 FFT Showing the Loop-Backed TM3.1a Waveform
   Figure 5-3 Zoom of the FFT Showing the Loop-Backed TM3.1a Waveform