TMDXIDK5718: How does I2C module respond to start and stop conditions from slave device?

Vikesh Subramanian

Part Number: TMDXIDK5718
Other Parts Discussed in Thread: AM5718

Tool/software:

Hello,

We are running TI-RTOS on the AM5718 using I2C to read data from an ADC. Due to noise, the ADC sometimes generates an incorrect signal that can be read as a stop or repeated start condition during read operations. I am looking to find what status codes will be returned by the I2C_transfer function will be under these conditions.

The following two waveforms are from a 1-byte write / 2-byte read from the ADC and show incorrect behavior from the ADC and the response of the AM5718.

False start condition:

False stop condition:

What does the I2C module return under these conditions and is there any way of detecting the error in software?

Thank you

10 months ago

0 Parth Nagpal 10 months ago

TI__Mastermind 42135 points

Hi,

Need to check this internally. Will get back to you by wednesday.

Regards,
Parth

0 Vikesh Subramanian 10 months ago in reply to Parth Nagpal

Prodigy 90 points

Hello Parth,

Thanks for your reply. Just wanted to check where things are on finding an answer to this?

Best,

Vikesh

0 Vikesh Subramanian 9 months ago

Prodigy 90 points

Hello Parth,

We have concluded that repeated starts return I2C_STS_SUCCESS. We are still trying to determine how to detect this condition and reject the invalid data being returned. Do you have any insight on how we can do this?

Thanks,

Vikesh

0 Vikesh Subramanian 9 months ago in reply to Parth Nagpal

Prodigy 90 points

Hello,

Are there any updates for this issue?

Thanks,

Vikesh

0 Karthikeyan S 9 months ago in reply to Vikesh Subramanian

TI__Expert 8720 points

Hi,

Sorry for the delay, Could you please share the detailed steps you are following for this? We are attempting to reproduce the error on our end.

Regards,

Karthik

0 Vikesh Subramanian 9 months ago in reply to Karthikeyan S

Prodigy 90 points

Hi Karthik, Thanks for your message! Though this problem is caused by EMI in our system, we have been able to recreate it by using an external microcontroller (pi pico) to generate the fault condition. We configured a GPIO to send the necessary acknowledge signals and generate the issue.

0 Karthikeyan S 2 months ago in reply to Vikesh Subramanian

TI__Expert 8720 points

Hi,

Vikesh Subramanian said:
Though this problem is caused by EMI in our system, we have been able to recreate it by using an external microcontroller (pi pico) to generate the fault condition

Is assistance still needed for this thread?

Regards,

Karthik

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TMDXIDK5718: How does I2C module respond to start and stop conditions from slave device?