AM625: I2C communication sometimes fails with MCU+SDK

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Part Number: AM625
Other Parts Discussed in Thread: SK-AM62B-P1

Tool/software:

I2C communication sometimes fails with MCU+SDK 10.01.33.
There are two symptoms.
① I2C_Open fails.
② An error occurs when transferring continuously.

For ①, the return value is NULL, and isOpen in the handle information passed as an argument remains false.
Since the probability of occurrence changes even when unrelated code is changed, I suspect it depends on the memory layout and timing.
What is causing the failure?

For ②, it occurred when performing two 1 byte reads with a 1 ms cycle.
I2C_STS_ERR or I2C_STS_ERR_TIMEOUT is returned.
Since it is operating at 400 kHz, 1 ms should be enough for communication to end.
Are there any precautions for use?

Best regards.

(c12efc99-2e63-4d04-a337-3737dc82fab4)

2 months ago

0 Tushar Thakur 2 months ago

TI__Mastermind 48868 points

Hi,

?? ?? said:
What is causing the failure?

How are you loading the binary to the target environment? Are you doing a CPU reset before loading the example again?

?? ?? said:
Are there any precautions for use?

Are there any other task running in the system other than I2C?

Regards,

Tushar

0 ?? ?? 2 months ago in reply to Tushar Thakur

Prodigy 70 points

Hi,Tushar

>How are you loading the binary to the target environment? Are you doing a CPU reset before loading the example again?

This environment is an R5 core. So after writing it to flash, I load only the symbols with the debugger.

>Are there any other task running in the system other than I2C?

There are other tasks running, but they are empty processes so I don't think it has any effect on the processing load.

Best regards.

0 Tushar Thakur 2 months ago in reply to ?? ??

TI__Mastermind 48868 points

Hi,

?? ?? said:
So after writing it to flash, I load only the symbols with the debugger.

I don't expect the same code to behave differently. Can you please tell us what modification you did?

?? ?? said:
There are other tasks running, but they are empty processes so I don't think it has any effect on the processing load.

Please try commenting the other processes and only run I2C task and check are you still getting timeout.

Regards,

Tushar

0 ?? ?? 2 months ago in reply to Tushar Thakur

Prodigy 70 points

>I don't expect the same code to behave differently. Can you please tell us what modification you did?

The only thing that has changed is that I2C_Open is called some time after the task is started, but the arguments etc. have not changed. Under what conditions does an error response occur?

>Please try commenting the other processes and only run I2C task and check are you still getting timeout.

I'll try it, but I'd also like to know the conditions under which an error occurs.

Regards,

0 Tushar Thakur 2 months ago in reply to ?? ??

TI__Mastermind 48868 points

?? ?? said:
Under what conditions does an error response occur?

You can check the I2C_open() API for this details. There are condition which checks for invalid I2C Parameters and return failure if any of those condition executes.

You can put a breakpoint on the API and debug it step by step to know what is causing failure at your end.

?? ?? said:
I'll try it, but I'd also like to know the conditions under which an error occurs.

From which API call are you getting I2C_STS_ERR or I2C_STS_ERR_TIMEOUT response?

Regards,

Tushar

0 ?? ?? 2 months ago in reply to Tushar Thakur

Prodigy 70 points

>You can check the I2C_open() API for this details. There are condition which checks for invalid I2C Parameters and return failure if any of those condition executes.

The same software gives an error response depending on the timing.
Can open fail due to hardware factors? It's difficult to detect through debugging.

>From which API call are you getting I2C_STS_ERR or I2C_STS_ERR_TIMEOUT response?

I2C_transfer returns I2C_STS_ERR or I2C_STS_ERR_TIMEOUT.

Regards,

0 Tushar Thakur 2 months ago in reply to ?? ??

TI__Mastermind 48868 points

Hi,

?? ?? said:
The same software gives an error response depending on the timing.
Can open fail due to hardware factors? It's difficult to detect through debugging.

Can you put a loop forever on places where I2C_transfer API is supposed to return status values? When the failure happens you can just halt the CPU and check the parameters value for inconsistency.

You can modify the driver code like below.

After making the changes in the driver code, rebuild the libraries and application.

The above will help you to narrow down the root cause for the issue.

Regards,

Tushar

0 Krithika Ravi 2 months ago in reply to Tushar Thakur

TI__Mastermind 20447 points

Hello,

Apart from sharing the results of the test Tushar requested for above for issue #2, please share the Linker and memory map files for Issue #1.

Regards,
Krithika

0 Jun Ito(AW) 2 months ago in reply to Krithika Ravi

TI__Genius 11065 points

Hi Krithika,

I shared Linker.cmd and memory map via TI Drive. Could you check those file and give them feedback?

- I2C communication is failed 80% after boot the system in 2ms.

- But there is no error happen after boot the system in 20ms.

- The failure does not happen when uncheck Blocking Mode of Enable Interrupt.

It seems that I2C driver is stack when timeout happen. it means that object->state doesn't become IDLE in i2c_v0_lld.c after communication timeout happen.

Please investigate this behavior as soon as possible.

Best regards,

Ito

0 Tushar Thakur 2 months ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Ito,

Jun Ito(AW) said:
I shared Linker.cmd and memory map via TI Drive. Could you check those file and give them feedback?

Please share the link to me as well.

Have you done the above suggested experiments to narrow down the issue?

Regards,

Tushar

0 Jun Ito(AW) 2 months ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tushar,

I send the linker cmd file and memory map to you via e-mail.

Could you please look into this?

Best regards

Ito

0 Tushar Thakur 2 months ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Jun,

I have not received any mail from you. Can you please check it once?

I have sent you mail also.

Regards,

Tushar

0 Jun Ito(AW) 2 months ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tushar,

It seem that I send the e-mail to you but it seems error happen. So I attached the files to webex chat. Could you check it?

Best regards,

Ito

0 Tushar Thakur 2 months ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Jun,

I have received the files over webex chat. Please allow some time to revert back.

Regards,

Tushar

0 Tushar Thakur 2 months ago in reply to Tushar Thakur

TI__Mastermind 48868 points

Hi Jun,

The linker.cmd file looks okay. Can you please provide the result of experiment suggested in earlier reply to narrow down the issue?

Regards,

Tushar

0 Jun Ito(AW) 1 month ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tushar,

It seem that this issue dosen't happen on SDK 11.0. I request to Krithika to investigate why this problem doesn't happen. Customer needs the reason.

Best regards,

Ito

0 Tushar Thakur 1 month ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Jun,

Thanks for the above update. I will check the above details and revert soon.

Regards,

Tushar

0 Jun Ito(AW) 1 month ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tushar,

Customer could reproduce the issue on SDK 10.2 on TI EVM. Please try to reproduce the issue with attached file on SDK 10.2.

I2C_test2.zip

I think after you reproduce the issue, you can understand the root cause and why this issue doesn't happen SDK 11.0.

Please investigate this?

Best regards,

Ito

0 Tushar Thakur 1 month ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Ito,

We have not reproduced the issue yet on our side. Meanwhile, I have checked the difference between the SDK versions for I2C drivers and there is only one major change.

Inside the ISR routine I2C_lld_controllerIsr API, driver is calling the I2C_lld_complereCurrTransfer API before the stop condition.

In the SDK v11.0, the I2C_lld_complereCurrTransfer API is called after the stop condition and checking for the error status.

Please refer below image.

You can try this changes in the SDK v10.1 and let us know if this works.

Regards,

Tushar

0 Jun Ito(AW) 1 month ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tushar,

Thank you very much for your help and working on reproduce the issue using customer shared the source code.

I would like to test, but I don't have enough bandwidth now. I'll ask them their is any trick to reproduce the issue.

Thanks a lots.

Best regards,

Ito

0 Tushar Thakur 1 month ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Ito,

Thanks for the update. We will wait for the results.

Regards,

Tushar

0 Jun Ito(AW) 1 month ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tusha,

Have you use attached source code(I2C_test2.zip) they created?

They said it is easy to reporduce the issue on SK-AM62B-P1 with SDK 10.

This applicaton will write the data to E2PROM continuasly.

- SDK 11 : The application write the data to E2PROM continuasly without error.

- SDK 10 : Communication error happen at first time.

Could you try to reproduce this issue?

And I'd like to reproduce this issue on my side after I receved the EVM.

>We have not reproduced the issue yet on our side.

Is it SDK 10.1?

Is I2C communication working continuasly?

Best regards,

Ito

0 Tushar Thakur 1 month ago in reply to Jun Ito(AW)

TI__Mastermind 48868 points

Hi Ito,

I have not tried their code on my end. I will try and let you know.

Regards,

Tushar

0 Jun Ito(AW) 1 month ago in reply to Tushar Thakur

TI__Genius 11065 points

Hi Tushar,

Thank you very much for you support.

Please try to reproduce the issue and investigate it.

Best regards,

Ito

0 Jun Ito(AW) 1 month ago in reply to Jun Ito(AW)

TI__Genius 11065 points

Hi Tushar,

Please try to reporduce the issue with the sample Pioneer provides.

Best regards,

Ito

0 Jun Ito(AW) 1 month ago in reply to Jun Ito(AW)

TI__Genius 11065 points

Hi Tushar,

Could you give me the update?

Best regards,

Ito

0 Jun Ito(AW) 1 month ago in reply to Jun Ito(AW)

TI__Genius 11065 points

This thread is moved to AM620-Q1: I2C communication sometimes fails with MCU+SDK

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AM625: I2C communication sometimes fails with MCU+SDK