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66AK2H06: Clock Stretching for I2C

Genius 4415 points
Part Number: 66AK2H06

Hi experts,

Q: Does the 66AK2H06 I2C support the clock stretching feature?

My customer is experiencing an Arbitration Lost error in I2C communication for a product using 66AK2H06 and is investigating the cause. Looking at the waveform at the time of the error, there is a point where the SCL suddenly goes from High to Low just before the data ACK, and we suspect that the slave side may have performed clock stretching.(66AK2H06 is the master side.)

There are many unclear points about the situation, but first of all, please let me know if the I2C of 66AK2H06 supports the clock stretching function.

Best regards,
O.H

  • Hello,

    Yes it does. Refer to this user guide:

    https://www.ti.com/lit/ug/sprugv3/sprugv3.pdf

    And this section:

    2.4 Clock Synchronization

    Regards,

    Kyle

  • Hello,

    Thanks for your reply. I have checked "2.4 Clock Synchronization" in the user's guide, but there is no mention of "Clock Stretching".

    Q: Am I correct in understanding that the "2.4 Clock Synchronization" function allows the 66K2H06 (master device) to automatically detect and respond to clock stretching when a slave device causes clock stretching?

    "2.4 Clock Synchronization" describes the case where there are two or more master devices. I understood that this is to determine which one to use when there are signals from more than one clock generator. There seems to be no mention of the case where a slave device causes clock stretching.

    Best regards,
    O.H

  • O.H.,

    This paragraph is related to the slave stretching the clock:

    If a device pulls down the clock line for a longer time, the result is that all clock generators must enter the wait state. In this way, a slave slows down a fast master and the slow device creates enough time to store a received data word or to prepare a data word to be transmitted.

    Regards,

    Kyle

  • Hello Kyle,

    I understood the content.

    Thanks for the replies and the support!

    Best regards,
    O.H