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Linux/DS90UB953-Q1: DS90UB953-Q1

Part Number: DS90UB953-Q1
Other Parts Discussed in Thread: DS90UB954-Q1

Tool/software: Linux

i use DS90UB953 and DS90UB954,now my question is  through DS90UB954 register 0x73 0x74,I know the video is 1080p,but my CPU don't receive DS90UB954 video date.i find <ds90ub954-q1.pdf> page 46,

To operate CSI-2 at speed of 400-Mbps mode, set CSI_PLL_CTL to 11b (0x1F[1:0] =11) to enable 400-Mbps operation for the CSI-2 Transmitters. Internal PLL and Timers are then automatically adjusted for the duced reference clock frequency. The REF_CLK_MODE bit should be set to 0 for this mode of operation. 

I can't find REF_CLK_MODE in this document,Please help me.Thank you very much.

  • sorry,mu question is about ds90ub954,not 953,thank you very much
  • Hi Lei,

    This line refers to a register write that was only required for pre-production parts. It will be removed from the next revision of the datasheet.

    To make the 400 Mbps CSI rate work, only the writes listed in the datasheet are required.

    Regards,
    Zoe
  • Thank you very much.But I don't understand,when i use the default 800Mbps,I can connet the 953,but when i change to 400Mbps,I cannot control the 953.

    Now i can't receive the 954's video date,i think maybe the 800Mbps is too high,my PCB can't transfer it,so I want to change to 400Mbps.

    If it is not this problem,any other suggestion?Thank you very much.

  • Hello,

    Can you share a register dump for the 954 and the 953?

    When you say you "cannot control the 953", do you mean that you can no longer read/write to the 953 registers? Or do you mean that you no longer see a video output from the 954?

    One thing to check is that you are following the procedure from Section 7.4.28.1 Enabling and Disabling the CSI-2 Transmitter in the 954 datasheet when you are modifying the settings on the CSI transmitter.

    Regards,

    Zoe

  • Thank you very mcuh,my cpu have receive the video date。 another problem,my video source is 1080p/30fs or 4M/30fs,but cpu only have received 1080p/10fs or 4M/10fs。The video is OK,but the frame rate only 10fps.
    My previous questions is because i don‘t follow the recommended timer settings for 400Mbps on page 40.
    Thank you very much.
  • Hi Lei,

    Glad to hear you solved your previous issue. Can you double check the configuration of the video source?

    The frame rate is not modified by the 953/954.

    Regards,
    Zoe