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Original question:

DS90UB953-Q1: serializer deserializer diagnostics

DS90UB953-Q1: ds90ub936

vineeth M
Prodigy 200 points
Part Number: DS90UB953-Q1

currently we are using ds90ub936 deserializer and ds90ub935 serializer. our camera is 1.3 MEGA pixel . we provide a external clock to CMOS  and deserializer. serializer working in internal asynchronous clock mode.any clocking issue will cause image data corruption? 

  • 0
    TI__Genius 11340 points

    Hi Vineeth,

    Your use case should be supported.

    Best,

    Jiashow

  • 0 in reply to Jiashow Ho
    Prodigy 200 points

    Hi, Jiashow,

    We need to configure around 200 registers in the image sensor.while configuring cmos registers, some registers (around 10 Registers)write is failed and showing i2cwrite error -6 ( Linux OS).what is the reason behind that? I have read the DS90UB936 & DS90UB935 status register.please find the attachment.

    Fullscreen observed_data.txt Download 
    SERIALIZER Observed Data 

0x51 =c0
0x52=67
0x53=01
0x54=00
0x55=ff
0x56=ff
0x57=00
0x58=07
0x59=07
0x5a=07
0x5c=ff
0x5d=06
0x5e=48
0x5f=00
0x60=00
0x61=2a
0x62=14
0x63=05
0x64=10


Deserializer Observed data


0x04=DF
0X24=00
0X29=00
0X50=65
0X51=00
0X52=00
0X53=02
0X54=00
0X55=00
0X56=00
0X57=00

  • 0 in reply to vineeth M
    TI__Genius 11340 points

    Hi Vineeth,

    Do you have more information on the error you're seeing? Is it a timeout (NACK)? Do the errors occur repeatedly with the same registers or appearing at random places?

    Usually if the issue is with NACK, I would suggest adding a delay between writes. Make sure clock stretching is supported.

  • 0 in reply to Jiashow Ho
    Prodigy 200 points

    Hi Jiashow,

    Every time write and read error occur in different registers.we are using ominivision camera ov2311.l have added 10 ms delay between the each read and write operation, but same result.

  • 0 in reply to vineeth M
    TI__Genius 11340 points

    Hi Vineeth,

    Do you have the right pull-ups? Can you probe the scope for the I2C transections?

  • 0 in reply to Jiashow Ho
    Prodigy 200 points

    I2C Wave forms looks ok. so we assume Pull -ups are correct.

    We probed the I2C data at both DESER and SER and whenever error happens our observation is below

    1. SOC is sending the correct I2C data on the bus at the DESER side

    2. But we did not observe the I2C transactions on the I2C side of SER

    3.LOCK and PASS status lines stays high during the error condition of I2C

    we have attached the i2c wave forms captured during I2C error conditions.

    note:Green - LOCK, Blue - PASS

    Green - LOCK, Blue - PASS


  • 0 in reply to vineeth M
    TI__Genius 11340 points

    Hi Vineeth,

    Let me clarify, you are writing 200 registers to the imager but only ~10 registers show errors?

    For the 10 register writes that show errors, you do not observe I2C on the serializer side, but for the 190 register writes you do?

    Are you setting the camera ID and aliases correctly? Are you selecting the RX port before writes?

  • 0 in reply to Jiashow Ho
    Prodigy 200 points

    Yes correct only 10 registers are showing errors. How to know Cmos is started the streaming through Fpd using status register of SERDES? We observed that during the failed cases Clock stretching is missing in the deserializer side.

  • 0 in reply to vineeth M
    TI__Genius 11340 points

    Hi Vineeth,

    Is it possible that the SoC somehow stops clock stretching during these transections?

    For your question regarding CMOS, you can configure PASS status on the deserializer to indicate valid frames received.