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Andres Cao
Andres Cao
Associate III
September 29, 2017
Question

HAL_ERROR in HAL_RCC_OscConfig()

  • September 29, 2017
  • 3 replies
  • 1684 views
Posted on September 29, 2017 at 18:13

Hi all!

I have an STM32L0 using the HSI to clock at 6MHz, and a LSE for the RTC.

Devices goes to sleep (STOP mode) and wakes up just fine.

But if I activate the RTC Alarm A interrupt, while restoring clocks I get a HAL_ERROR in the HAL_RCC_OscConfig() function.

More precisely here:

/* Check if the PLL is used as system clock or not */

if(__HAL_RCC_GET_SYSCLK_SOURCE() != RCC_SYSCLKSOURCE_STATUS_PLLCLK)

{

   .....

}

else

{

   return HAL_ERROR;

}

Any clues into this? 

Thanks!!!
    This topic has been closed for replies.

    3 replies

    Tesla DeLorean
    Tesla DeLorean
    Guru
    September 29, 2017
    Posted on September 29, 2017 at 18:19

    Decode the RCC state before that, make sure the HSI is clocking, the PLL is locked and sourced correctly.

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    Andres Cao
    Andres CaoAuthor
    Associate III
    October 3, 2017
    Posted on October 03, 2017 at 13:06

    Thank you

    Turvey.Clive.002

    for the suggestions.

    I have gotten a little bit deeper and realized that the device is actually not going to sleep, and this happens sometimes every couple of minutes, or could be a couple of days. If the HAL_RCC_OscConfig() is calledwhen the device is awake then it fails and goes to the Error_Handler();. Of course, it shouldn't be called when the device is awake, but this would happen if the device fails to go to sleep.

    I have the following function to go to sleep:

    void enterStopMode(void){

    if (HAL_RTCEx_SetWakeUpTimer_IT(&hrtc, 9, RTC_WAKEUPCLOCK_CK_SPRE_16BITS) != HAL_OK) {

    TRACE_DBG_H('HAL ERROR -> HAL_RTCEx_SetWakeUpTimer_IT\n');

    }

    HAL_CRC_DeInit(&hcrc);

    HAL_I2C_DeInit(&hi2c1);

    HAL_I2C_DeInit(&hi2c2);

    HAL_I2C_DeInit(&hi2c3);

    isSleep=true;

    TRACE_DBG_H('STOP\n');

    HAL_UART_DeInit(&hlpuart1);

    __HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);

    __HAL_RCC_WAKEUPSTOP_CLK_CONFIG(RCC_STOP_WAKEUPCLOCK_MSI);

    HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);

    }

    Sometimes this function doesn't go to sleep at all and code continues execution, where the HAL_RCC_OscConfig() is called and it fails as expected.

    I noticed that in the Reference Manual (

    http://www.st.com/content/ccc/resource/technical/document/reference_manual/2f/b9/c6/34/28/29/42/d2/DM000957pdf/files/DM000957pdf/jcr:content/translations/en.DM000957pdf

    ) page 161, Table 37, it says:

    Note: To enter the Stop mode, all EXTI Line pending bits (in Section 5.6: EXTI pending register (EXTI_PR)), all peripherals interrupt pending bits, the RTC Alarm (Alarm A and Alarm B), RTC wakeup, RTC tamper, and RTC time-stamp flags, must be reset. Otherwise, the Stop mode entry procedure is ignored and program execution continues.

    The only interrupt is the SysTick one. Could this be a race condition inside the

    HAL_PWR_EnterSTOPMode that there's just an interrupt event before entering stop and makes it fail as per the note above?

    void HAL_PWR_EnterSTOPMode(uint32_t Regulator, uint8_t STOPEntry)

    {

    uint32_t tmpreg = 0U;

    /* Check the parameters */

    assert_param(IS_PWR_REGULATOR(Regulator));

    assert_param(IS_PWR_STOP_ENTRY(STOPEntry));

    /* Select the regulator state in Stop mode ---------------------------------*/

    tmpreg = PWR->CR;

    /* Clear PDDS and LPDS bits */

    CLEAR_BIT(tmpreg, (PWR_CR_PDDS | PWR_CR_LPSDSR));

    /* Set LPSDSR bit according to PWR_Regulator value */

    SET_BIT(tmpreg, Regulator);

    /* Store the new value */

    PWR->CR = tmpreg;

    /* Set SLEEPDEEP bit of Cortex System Control Register */

    SET_BIT(SCB->SCR, SCB_SCR_SLEEPDEEP_Msk);

    /* Select Stop mode entry --------------------------------------------------*/

    if(STOPEntry == PWR_STOPENTRY_WFI)

    {

    /* Request Wait For Interrupt */

    __WFI();

    }

    else

    {

    /* Request Wait For Event */

    __SEV();

    __WFE();

    __WFE();

    }

    /* Reset SLEEPDEEP bit of Cortex System Control Register */

    CLEAR_BIT(SCB->SCR, SCB_SCR_SLEEPDEEP_Msk);

    }

    I'm not entirely sure if this could be the case. Any opinions?

    Thanks all for your input.

    Andrés

    Andres Cao
    Andres CaoAuthor
    Associate III
    October 4, 2017
    Posted on October 04, 2017 at 11:20

    Hi all!

    Can anyone help me as to how to avoid this Stop mode entry ignored? I checked EXTI_PR and it is 0, but still Stop mode is ignored due to the Systick timer, I think. 

    Note: To enter the Stop mode, all EXTI Line pending bits (in Section 13.5.6: EXTI pending register (EXTI_PR)), all peripherals interrupt pending bits, the RTC Alarm (Alarm A and Alarm B), RTC wakeup, RTC tamper, and RTC time-stamp flags, must be reset. Otherwise, the Stop mode entry procedure is ignored and program execution continues.

    Thanks in advance!

    Andrés  
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