This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TSW14J56EVM: ADC12J4000EVM decimation

Part Number: TSW14J56EVM

Hello,

I'm using ADC12J4000_D4_DDR profile and noticed it has two channels and data that is captured is almost identical in both of them and so it effectively makes it 1G of samples I would like to use whole 2G samples with decimation I tried to change number of channels in INI but it seems like not giving me appropriate output I suspect there is something that I need to change or don't understand?

Unrelated to this I found an issue with HSDC GUI if I capture 2G of samples 4GB temp file is created ADCTempX.bin (X - channel number) in HSDC folder but when I save samples from UI only first 2GB is copied into destination file looks like UI logic sees 1 channel and assumes max channel size is 1G (2GB). I ended up using temp file as of right now but just wanted to let you know.

Also can I change somehow analysis window size beyond 512K samples?

PS: I'm using HSDC GUI version 4.50.

Thank you,

V.

  • Hi Volodymyr

    In the ADC12J4000 decimation modes, the output data is always output as a pair of 15-bit complex I+Q values. Please refer to Figure 48, and section 7.3.6.4 of the ADC12J4000 datasheet.

    Because the data is output as I+Q pairs, the effective output bandwidth is higher than it would be if the decimated data was real only.

    In HSDC Pro, the upper 15 bits if I data are used for Channel 1, and the upper 15 bits of Q data are used for Channel 2. To view the full complex spectrum set the data analysis mode to Single Tone, and change the main display format from Real FFT to Complex FFT.

    I think the issue with the file size is that the ADCTempX.bin file saves the information for both the Ch1 and Ch2, but in the HSDC Pro display you only view/analyze one channel at a time. When you Save Raw ADC Codes or Save I32 Codes you only save the 2GB samples for that channel. You will need to first save the values for Channel 1/2 and then select Channel 2/2 to save those values.

    It may be possible to include the analysis window size, but doing so may make HSDC Pro unstable due to memory issues. What window size are you hoping for?

    Best regards,

    Jim B

  • Hi Jim,

    Thank you for explanation on decimation.

    Regarding Save Raw ADC Codes I'm sorry if I wasn't clear issue happens only when I select bypass mode and so there is only one channel and that's why ADCTemp file is 4GB in case of decimation HSDC Pro creates two files 2GB each and when you Save Raw  ADC Codes then UI takes both channels and combines into one 4GB file with assumption that user know how many channels it was when you try two open it HSDC Pro later.

    I was hoping it will be more customizable nowadays computers have enough of memory to work with large data sets. Actual struggle that I have is when I capture a lot of samples navigation becomes a problem because navigation window in upper graph in HSDC Pro disappears and I have to zoom-in and then drag it. Ideally would be if HSDC Pro had left/right buttons to move analysis window by N samples as of right now I created quick app to load raw data and do better navigation:

    Thank you,

    V.

  • Hi V.

    I'm glad you are able to achieve what you intended. Your custom navigation window looks good.

    Let us know if you need anything else.

    Best regards,

    Jim B