This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS90UB988-Q1: IIC does not forward

Part Number: DS90UB988-Q1

When conducting communication tests, there is a chance that 988 will not forward IIC messages. When we separately connect the IIC tool to 988 and the MCU, the tool can send messages to the MCU. Therefore, it is determined that 988 will not forward IIC messages

  • 您好,
    已经收到了您的案例,调查需要些时间,感谢您的耐心等待。

  • Thank you for sharing this issue.

    Is my understanding you are trying to pass I2C message

    We will need some more information on the issue to deduce root cause.

    Can you share the following information:

    When conducting communication tests, there is a chance that 988 will not forward IIC messages
    • How often does i2c forwarding to 988 occur and what is the failure rate
    • Have you configured the correct target address for forwarding and the correct port to forward on?
  • The first step is that our communication is normal
    The second step is to use jlink to enter DEBUG mode and interrupt the operation of the MCU
    In the third step, when the MCU starts working again, there is a probability that communication anomalies will occur, and the host anomaly will return as NACK.
    100% reproducible

  • Where exactly are the IIC messages not being forwarded?

    Can you please provide a block diagram to show where messages are not received?

    My assumptions for why the message does not forward:

    • The connection between the SER and DES is interrupted (loss of LOCK)
    • The SoC on the SER or the connected MCU is also sending a transaction at the same time (multiple controller contention on the bus)

    Can you also please provide the statistics, such as:

    • How many times this issue will happen
    • What are the conditions or timing for this to occur
    • The number of units that are affected by this issue and the number of total units?

    Thanks,