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Linux/TMS320DM8168: TMS320DM8168

Part Number: TMS320DM8168

Tool/software: Linux

It seems that when a Samsung 75" monitor (UN75J6300AF )  is controlled by CEC from an TMS320DM8168 based HDMI source , it goes from standby state to powering up when the HDMI source is booting up.During this process, somehow EDID was not read properly from this Samsung model.

Only 160 bytes of the 256 bytes EDID data were obtained by the TI81xx hdmi driver.

The driver checks EDID byte 164-166 to determine if the monitor is capable of HDMI.

In this case, the check failed and TMS320DM8168 based HDMI source only drove DVI signal to the Samsung monitor without audio packets.

According to the HDMI spec , The Samsung UN75J6300AF can de assert the HPD line to indicate the E-EDID need to be re-read and only when the HPD is high the HDMI source  shell assume the  EDID is readable , so I would like to know why the TMS320DM8168 is not aborting the EDID read transaction or trying to re-read the EDID after the HPD is reasserted.

See attached Scope snapshot .

 

  • Hi Koby,

    Do you use DM816x TI EVM or custom board? Do you use DM816x EZSDK or PSP or else? Which version?

    Do you use HDMI registers SYS_STAT[1] and INTR1[6] in your code?

    "According to the HDMI spec" - which spec exactly is this?

    See if the below e2e threads will be in help:

    e2e.ti.com/.../190364
    e2e.ti.com/.../267007

    http://processors.wiki.ti.com/index.php/TI81XX_PSP_HDMI_Driver_User_Guide

    Regards,
    Pavel

  • Thanks Pavel for your support : 

    1. This is a custom board that was shipped  world wide for 5 years  ( 50000 units ) with no such issues .

    2 + 3 . Will check and let you know about the version and registers being used .

    4. Spec 1.3 and above : 

    An HDMI Sink shall indicate any change to the contents of the E-EDID by driving a low voltage
    level pulse on the Hot Plug Detect pin. This pulse shall be at least 100 msec.

  • koby rosenberg said:
    1. This is a custom board that was shipped  world wide for 5 years  ( 50000 units ) with no such issues .

    I would suggest you to check also DM816x TI EVM with that specific monitor.

    Do all these 50000 custom boards have the same issue with that specific monitor or just few of them?

    koby rosenberg said:
    4. Spec 1.3 and above : 

    DM816x HDMI is 1.3a-compliant transmitter for digital video and audio data to display devices. So it should act by this spec.


    Regards,
    Pavel