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DS90UB948-Q1: Asking for the recommendation on DS90UB948/949 setting

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Replies: 5

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Part Number: DS90UB948-Q1

Hi Team,

Customer is designing DS90UB948/949. And would you please help for the following questions.

Q1. Will 948/949 detect and determine the input source format and LCD panel are match or not? Then, the LCD can normal display under the 948 MODE_SEL0 set to corresponding proper setting.

Q2. For case 2, do customer need to adjust 948/949 output resolution?

 

Here are the experiment on customer’s board. 

case 1. Customer used HDMU pattern generator to generate the signal that matching the LCD panel spec as below.

Customer need to set MODE_SEL0 to1.241V

LCD panel can display normal.

Case 2. Customer used Notebook(1366 X 768) and android phone(un-known resolution) to output the HDMI signal

customer need to set ODE_SEL0 to 2.642V or 3.3V

LCD panel can be partial display normal.

In case 2, the display resolution is not correct form the LCD panel. 

Here are the original Notebook and Android phone content on notebook and phone.

However, after 949 to 948, the content showed on LCD panel are as below.

For notebook case, the content width is becoming wider. For the phone, it the scale on length and width are not as same as phone content.

Here are the block diagram, schematic and LCD panel spec.

txn.box.com/.../yxzhj85v2kllno1uudo50f9ytdhg4v34

BR,

SHH

 

  • Hi SHH,

     Thank you for including the datasheet.  Exploring this issue and will send an update tomorrow.

    Sincerely,
    Bryan Kahler

  • In reply to Bryan Kahler:

    Hi SHH,

    For automatic detection of a display, it will need to provide an EDID profile that lists all the capabilities of the display.  After parsing the EDID information, the video source can send back video data with proper timing and resolution the display can support.

    For both of these issues, please look into EDID and timing/resolution settings.  The 4 types of EDID configurations supported by the 949 are described in sections 7.3.4 for the data sheet.

    The EDID information is accessible through the DDC interface and will need to comply with the EDID requirements given in the HDMI v1.4b specification.

    With respect to case 2, please use the internal pattern generator to test and determine the proper timing settings then make sure that the EDID information matches.

    Sincerely,
    Bryan Kahler

  • In reply to Bryan Kahler:

    Hi SHH,

    Haven't heard from you in a while - hopefully no news is good news and the issue is now resolved.  If so, to help enable others that may have the same question find the correct answer, please press the green 'this resolved my issue' button.

    If not, please let me know what other issues related to the original question remain.

    Sincerely,
    Bryan Kahler

  • In reply to Bryan Kahler:

    Hi Bryan,

    thanks for help. I will loop you in the customer's discussion mail.

    BR,

    SHH

  • In reply to SHH:

    Thanks SHH,

    The thread continues here: https://e2e.ti.com/support/interface/f/138/t/859149

    Sincerely,
    Bryan Kahler