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Original question:

DS90UH949-Q1: How to enable HDMI interrupt for monitoring HDMI hot plug detect ?

DS90UB949-Q1: How to make HDMI interrupt work

PYTsai
Genius 11940 points
Part Number: DS90UB949-Q1


Hi 

We had connected DS90UB949EVM with DS90UB940EVM

and below are the status screen shot and the register setting we done. HDMI source now is connected to DS90UB949 EVM, We use scope to monitor the INTB pin, but not see it goes down to issue an interrupt. 

Anything miss in our setting ? thanks!

  • 0
    TI__Mastermind 25955 points

    Hi PYTsai,

    Please perform a read of the HDCP_ISR to clear the interrupt.  Also, make sure the signal in is not high and immediately triggering the interrupt + latch.

    Sincerely,
    Bryan Kahler

  • 0 in reply to Bryan Kahler
    TI__Genius 11940 points

    Hi Bryan,

    We followed the above suggestion, not yet able to make it work. Our goal is to detect the +5V is present even their is no HDMI data is sending. 

    In our testing we do not plug in the HDMI source, instead, we only pull high the +5V pin. Below are the screen shot.

    May i know if only +5V present but no HDMI signal is sending, will this trigger the HDMI interrupt ? 

    Or it required the HDMI video source is linked to enable the HDMI interrupt ?

  • 0 in reply to PYTsai
    TI__Mastermind 25955 points

    Hi PYTsai,

    Please check register 0x50 BRIDGE_STS.  Bit 7 indicates the HDMI interface has detected valid voltage on the RX_5V input.  Bit 6 indicates if an HDMI interrupt is pending. 

    Please confirm that in hardware the INTB pin is pulled up to VDDIO with a 4.7 KOhm resistor and the REM_INTB pin is pulled up to 1.8V with a 4.7 KOhm resistor.

    Please also confirm that there is valid lock between the devices prior to the test.

    If issues persist, please send a scope shot that shows INTB on the 949 and the corresponding interrupt input pin on the 940.

    Sincerely,
    Bryan Kahler

  • 0 in reply to Bryan Kahler
    TI__Genius 11940 points

    Bryan,

    We are not able to pull up REM_INTB pin to 1.8V. Because on the DS90UB949 EVM that I have, there is no trace on REM_INTB pin to connect it to outside. 

    I saw REM_INTB is an output pin and we do not use it (we use INTB), does it matter left it open ? 

    Thanks!

    PY Tsai

  • 0 in reply to PYTsai
    TI__Mastermind 25955 points

    Hi PY Tsai,

    By default on the EVM it should be pulled high to VDDIO, unless your board has been reworked.   Please see below:

    Please let me know if you run into any other issues.

    Sincerely,
    Bryan Kahler

  • 0 in reply to Bryan Kahler
    TI__Genius 11940 points

    Bryan,

    Thanks! We decide to use GPIO to do this function.  

    Regards.