I2c clock line low for unusually long time without client clock stretch

sathishkumars — Thu, 15 Mar 2018 12:52:35 GMT

I2c clock line low for unusually long time (10ms) between a block read operation, and client times-out on the i2c transaction. We have checked with a series resistor close to client to see if client is stretching the clock, but client is not.
And there are no other clients on this bus. What are the circumstances that SoC introduces so much latency. Attached is a snapshot of i2c trace captured.

Re: I2c clock line low for unusually long time without client clock stretch

kerryzhou — Fri, 16 Mar 2018 06:27:36 GMT

Hi Sathishkumar S,

Please tell me what the kinetis chip you are using? Is it I2C master or slave?

From your wave, you can find the clock is also sent after 10ms:

So, this phenomena should caused by your code, it seems your I2C send process is interrupt by other things which have higher priority.

Please double check your code process.

Wish it helps you!

Have a great day,
Kerry

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topic Re: I2c clock line low for unusually long time without client clock stretch in Kinetis Microcontrollers

I2c clock line low for unusually long time without client clock stretch

Re: I2c clock line low for unusually long time without client clock stretch