RT685 I3C port - pins 2_29, 2_30 - Is IOCON ODENA Open-drain mode enable ignored?

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Pins set to mode 1 (I3C0__SCL, I3C0__SDA).

I do not see a difference whether the IOCON ODENA (Open-drain mode enable) bit is set or not.

I would expect, especially operating in I2C mode, it needs to be open-drain to work.

Thanks,

Dan

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Thank you.

We are using the port in I2C mode and have a pull-up on the data line.

[Dezheng_Tang · Accepted solution]

Hi,

    Bit 10 is the pseudo open drain configuration. This bit has no effect if you use I3C controller pins for I2C communication.

That’s why we mentioned this in our spec.

Once you configure I3C_PUR pin, it’s internally pull SDA high. If you don’t use PUR pin, you will need to have external Pull-up on SDA line for I2C communication. Either way, it’s needed when bus is in open drain condition.

More details on the bus conditions, push-pull or open-drain, can be found on MIPI I3C spec. v1.1, section 5.1.3.

Tom