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DS90UB954-Q1: Registers to check whether video is correctly received

Masaru Oinaga
Expert 4895 points

Part Number: DS90UB954-Q1

Hello, Team,

We would like to know if there is a register which the customer can check whether video is correctly received at Des side after recovering from disconnected state.

Currently, when the connection between Ser/Des is lost, they checked Lock status, I2C status, as well as VSYNC at the image processing SoC side.
In order to consider a situation where SoC cannot detect the video loss, it would be nice if there is a register which we can read the status of the video output.
By checking the register, the system would know whether video image is correctly recovered from loss.

The register could be on either Ser/Des, but Des would be better.

Best Regards,
Masaru Oinaga

  • 0
    TI__Expert 4895 points

    What we have in mind is something like reading status registers such as 0x4E, 0x51 might do the job.

  • +1 in reply to Masaru Oinaga
    TI__Guru** 116990 points

    Hello Masaru,

    yes, there are more than one way, for example:


    1) Monitor registers 0x73 and 0x74. If line count is 0, this means you are not receiving and video.
    2) configures PASS conditions for the Port selected in 0x4C. The status are shown in reg 0x4D and on PASS / LOCK pins.


    If you write 0x7D[1:0] = 1, then you can monitor reg 0x4D[1]. Note: reg 0x7D and 0x4D are port specific, so if you want to monitor PASS for Rx Port0, you need to write first 0x4C=0x01, and if you want to monitor PASS or Rx Port1, you need to write first 0x4C=0x12

    You can also configure PASS to show the status of one Rx Port, or both Rx Ports, if you modify reg 0x0C[5:4].

  • 0 in reply to Hamzeh Jaradat
    TI__Expert 4895 points

    Hello, Hamzeh,

    Thank you very much for your kind support.

    1)

    Hamzeh Jaradat said:
    1) Monitor registers 0x73 and 0x74. If line count is 0, this means you are not receiving and video.

    So this register monitors the LINE count information, and needs to enable an interrupt which causes LINE_COUNT?
    If so, please tell us how.

    Also, what if the video image is not received?
    a) It remembers the line count of the last frame and read it so that the it can latch it with the latest value -> read multiple times and confirm whether it stays 0?
    b) The line count immediately goes to 0 when , therefore reading one time is enough?

    2)

    Hamzeh Jaradat said:
    2) configures PASS conditions for the Port selected in 0x4C. The status are shown in reg 0x4D and on PASS / LOCK pins.

    Lock = detection of whether video + transmission are both dead?

    3)

    Also, I think the device should be in LP mode if video is not coming.
    LP mode has several status (00/01/10/11); can we use this to check whether the video signal is coming or not?

    Thanks,
    Masaru

  • +1 in reply to Masaru Oinaga
    TI__Guru** 116990 points

    Hello Masaru,

    1) No, you do not need to enable interrupt for counting the lines. It will start counting as soon as it receives a valid frame.

    If you lose the connection, or no more frames are incoming, line count will go to 0.

    2) LOCK does not care about Video. It cares only about FC transmission.

    3) The CSI lanes will be in LP mode if there are not transmitting video at the output. Please note, having LP does not mean you are not receiving video at the input, but it means you have no video at the output.

    If you want to know if there is video or not, please use PASS function as I told you above.