S32K311 Lpuart_Lin Slave always returns RX_HEADER_ERROR / RX_OVERRUN_ERROR

[johns_chuang]

Dear Team,

We are trying to enable the Lpuart_Lin (Slave) functionality on the S32K311, and we are referencing the example Lin_Ip_FrameTransfer_S32K344, using Lpuart_Lin_Ip_Init and Lpuart_Lin_Ip_GetStatus.

After the Master transmits a LIN frame:
[0x00, 0xFF, 0x80, 0x11, 0x6E]

The return status from Lpuart_Lin_Ip_GetStatus remains stuck at LPUART_LIN_IP_STATUS_RX_HEADER_ERROR.

Additionally, in the interrupt callback LpuartSlaveCallback, the status is always LPUART_LIN_IP_RX_OVERRUN_ERROR.

Do you have any suggestions on what we should check, or recommended changes we could try?

Thank you in advance for your support.

Best,

Johns

[danielmartynek · Accepted solution]

Hi @johns_chuang,

I finally managed to reproduce the issue during testing.

It turns out the problem was not related to the clock configuration after all.

I was able to replicate the issue on my EVB. To do so, I had to switch the LIN hardware to UART2 (PTD6, PTD7).

Once I removed all custom interrupt handling, the communication started working correctly.

These are the changes: 

You need to select the handler from Lpuart_Lin_Ip_Irq.c

Regards,

Daniel

[johns_chuang]

Hi Daniel, Do you know why I can only read the first byte? The BUFFER_SIZE in LinLpuartPdu is set to 3, but I’m only able to read the first byte — the remaining two bytes are both 0.

[danielmartynek]

Hi @johns_chuang,

Please create a new thread and describe it in details.

[danielmartynek]

Hi @johns_chuang,

The RX_HEADER_ERROR you're encountering is likely due to a timing mismatch..

Have you had a chance to measure the LIN signal using an oscilloscope? 

I reviewed the system clock configuration in your test project and noticed that it is not set up correctly.

If you want to have CORE_CLK = 48MHz, use Option D - Low-Speed Run mode (CORE_CLK @ 48 MHz), RM rev10, Table 162.

Thank you,

BR, Daniel

[johns_chuang]

Hi Daniel,

Sorry, I’m still getting used to the S32DS interface.
Could you please explain in more detail what you meant by the system clock error?
How should I correctly configure it to 48 MHz?

Currently, I’m trying to receive 1 byte of LIN data:

Eventually, I plan to work with 8 bytes of LIN data:

Thank you for your support.

Best,

Johns

[danielmartynek]

Hi @johns_chuang,

Before we can proceed further, the system clock configuration must be corrected - use the S32DS GUI (configuration tool).

Please note that NXP does not guarantee the functionality of the MCU if the ratios between the system clock domains deviate from an approved configuration. Using unsupported clock settings may lead to unpredictable behavior.

If your target is to run CORE_CLK at 48 MHz, you must configure all system clocks according to Table 162, Option D – Low-Speed Run mode (as per RM Rev. 10). 

Thank you,

BR, Daniel

[johns_chuang]

Hi Daniel,

Clock has been fixed, but the issue still persists. Could you kindly advise what I should check next? 

Thank you again for your support.

MCU：S32K311

S32DS ver. 3.6.2

SDK：RlatformSDK_S32K3_S32K311_M7 v5.0.0

Best,

Johns

[danielmartynek]

Hello @johns_chuang,

I'm sorry for the delay.

What is the baud rate of the LIN signal? Can you measure that?

Also, can you share the LPUART_0 registers after initialization?

Thank you,

BR, Daniel

[johns_chuang]

Hi Daniel,

The LIN baud rate is 19200 bps.

Are you referring to the LPUART_0 registers shown in this image?

Thank you for your help.

Best,

Johns

[johns_chuang]

Sorry, Sync was wrong. Correct LIN signal: [0x00, 0x55, 0x80, 0x11, 0x6E], ID is 0x00.