STM32CubeMX does not preserve conditional RTC initialization (it reinitialize when backup register is set)

[gianmarco.cerutti]

Hi ST Support Team,

I am using MXCube for STM32U5A5VJ. I have enabled the RTC, and cube generates the following Init Function. In this way, everytime I restart the controller, the RTC date is gonna be overwritten. In practice, I would like to have the bracket at line 9 down in line 21. Thank you for your support.

Best Regards, 

Gianmarco Cerutti

void MX_RTC_Init(void)
{
...
  /** Initialize RTC and set the Time and Date
  */
  if(LL_RTC_BKP_GetRegister(RTC,LL_RTC_BKP_DR0) != 0x32F2){

    LL_RTC_BKP_SetRegister(RTC,LL_RTC_BKP_DR0,0x32F2);
  }
  RTC_TimeStruct.Hours = 0x0;
  RTC_TimeStruct.Minutes = 0x0;
  RTC_TimeStruct.Seconds = 0x0;

  LL_RTC_TIME_Init(RTC, LL_RTC_FORMAT_BCD, &RTC_TimeStruct);
  RTC_DateStruct.WeekDay = LL_RTC_WEEKDAY_MONDAY;
  RTC_DateStruct.Month = LL_RTC_MONTH_FEBRUARY;
  RTC_DateStruct.Day = 0x11;
  RTC_DateStruct.Year = 0x25;

  LL_RTC_DATE_Init(RTC, LL_RTC_FORMAT_BCD, &RTC_DateStruct);
...
}

[Ghofrane GSOURI]

Hello @gianmarco.cerutti 

CubeMX will overwrite any changes you make outside the /* USER CODE BEGIN ... */ and /* USER CODE END ... */ blocks.

Try to put your code in the user section.

THX

Ghofrane

[gianmarco.cerutti]

Thank you for your answer. The problem is that the cube-generated code is resetting date by reboot. I am using the LL library.

[Ghofrane GSOURI]

Hello @gianmarco.cerutti 

As a workaround, copy and paste the MX_RTC_Init function into the user code section and make the required modifications.

void MX_RTC_Init(void)
{
...
  /** Initialize RTC and set the Time and Date
  */
  if(LL_RTC_BKP_GetRegister(RTC,LL_RTC_BKP_DR0) != 0x32F2){

  LL_RTC_BKP_SetRegister(RTC,LL_RTC_BKP_DR0,0x32F2);
  RTC_TimeStruct.Hours = 0x0;
  RTC_TimeStruct.Minutes = 0x0;
  RTC_TimeStruct.Seconds = 0x0;

  LL_RTC_TIME_Init(RTC, LL_RTC_FORMAT_BCD, &RTC_TimeStruct);
  RTC_DateStruct.WeekDay = LL_RTC_WEEKDAY_MONDAY;
  RTC_DateStruct.Month = LL_RTC_MONTH_FEBRUARY;
  RTC_DateStruct.Day = 0x11;
  RTC_DateStruct.Year = 0x25;

  LL_RTC_DATE_Init(RTC, LL_RTC_FORMAT_BCD, &RTC_DateStruct);
...
}
}

Then, go back to CubeMX and untick the "Generate code" option for MX_RTC_Init.

This way, CubeMX will not generate the MX_RTC_Init function, and you will already have the customized function with your modifications.

Remember to call your modified MX_RTC_Init function in the main function to ensure the RTC is properly initialized.

THX

Ghofrane 

[gianmarco.cerutti]

Thank you for the solution. This is actually what I have been doing. However, I would like CubeMX to do the job for me. Is there any way I can change the code generation in CubeMX? It looks like a bug — is it going to be fixed in a new release?

[Ghofrane GSOURI]

Hello @gianmarco.cerutti 

I appreciate you bringing this issue to our attention.

A ticket has been escalated to our development team to address and correct the current behavior.

Internal ticket number is 219211 

I will keep you posted with updates.

THX

Ghofrane