• Resolved

DS90UH941AS-Q1: query for the image sync when I use split function in Ser IC

Intellectual 840 points

Replies: 7

Views: 41

Part Number: DS90UH941AS-Q1

Hi TI,

There is the image tearing issue in my system.

the System has a configuration like below: 

TI 941 Ser IC TI 948 Des IC  #1 
TI 948 Des IC  #2 

If host device send the merged image to TI 941 and I use Splitting function of TI 941 ans send to each TI 948 des by half,  

q1) could "TI 941 Ser IC" send synchronous image to each TI 948 ?

q2) in this situation (using splitting function), is there any other method to check frame sync in TI 941 or TI 948 ? 

q3) by the splitting function of TI 941 Ser, is it possible to make the tearing issue ?? 

                               

Thanks 

  • + add explanation : 

    of course, now I am using symmetric splitting in TI 941. 

  • In reply to Minwoo Song:

    Hi Minwoo,

    Thank you for the clarification that symmetric splitting is being employed.

    Could you please send me an image of the tearing that is occuring?  Tearing may be due to incorrect timing parameters on the display.

    If you use patgen with the device, do you see tearing?

    Please try patgen on each individual 948 first.  With the local patgens working, please use patgen from the serializer.  With displays working confirmed with both local and remote pattern generation, then test the source again.

    With respect to sync, the images are asynchronous but streamed from the same source.  The sync could be measured for your individual implementation by transmitting a varied test pattern and recording both displays in the same field of view with a high speed camera.

    Sincerely,
    Bryan Kahler  

  • In reply to Bryan Kahler:

    Hi Bryan, 

    Thanks for your answer, and 

    I will ask SW team to share tearing image for this. 

    after reading your answer, I requested Pattern Generation in TI 941, but out SW engineer told me that, 

    in Splitting mode, the Pattern Generation by TI 941 can't be supported. <-- he heard this from TI. 

    q1) and I wonder, in splitting mode, can I use pattern generation function in TI 941 ? 

    q2) and one more question for Pattern gen to check tearing issue.

    - pattern gen image is fixed image, and maybe there is no any tearing // <-- we already checked this by Host pattern (fixed) image. 

    - and so, I wanna say, fixed image (pattern) is not suitable for this debugging. 

    How about your opinion ? 

    Thanks 

  • In reply to Minwoo Song:

    Hi Minwoo,

    Your engineer is absolutely correct.   After testing PATGEN on each 948 to display to confirm timing of the display, please test the screens individually using the PATGEN from the serializer to confirm timing is configured and proper across the link.

    This aim here is to confirm configuration and reduce the possible error space down to just the splitting settings.

    With all of the above working, we can then focus on the image from the SOC and splitting settings.

    Sincerely,
    Bryan Kahler

  • In reply to Bryan Kahler:

    Hi Bryan, 

    Very thanks for your answer, 

    With our SW engineer, I checked PATGEN from the serializer, 

    and, I saw no tearing issue with PATGEN image. 

    and so, for our timing setting,  I think that there is no timing problem. 

    is there any other check guide ? 

    Regards,

     

  • In reply to Minwoo Song:

    Hi Minwoo,

    This is good news.  Timing is good individually from the des to the display and from the ser over fpd link to the display.

    Next step is to look at the splitting configuration.

    This app note describes splitting of the 941as: https://www.ti.com/lit/an/snla308/snla308.pdf

    A programming example is given on page 16.

    Please describe your configuration and programming steps.

    Sincerely,

    Bryan Kahler

  • In reply to Bryan Kahler:

    Hi Bryan,

    Thanks for your guide.

    I asked this app note to our SW engineer. and he will re-check his setting comparing with it. 

    after that I will ask again. 

    Regards,