RCC Private Functions

Functions
static HAL_StatusTypeDef	RCC_SetFlashLatencyFromMSIRange (uint32_t msirange)
	Update number of Flash wait states in line with MSI range and current voltage range. More...
static uint32_t	RCC_GetSysClockFreqFromPLLSource (void)
	Compute SYSCLK frequency based on PLL SYSCLK source. More...

Detailed Description

Function Documentation

RCC_GetSysClockFreqFromPLLSource()

static uint32_t RCC_GetSysClockFreqFromPLLSource ( void  )

static

Compute SYSCLK frequency based on PLL SYSCLK source.

Return values

SYSCLK

frequency

Definition at line 1807 of file stm32l4xx_hal_rcc.c.

{
  uint32_t msirange = 0U;
  uint32_t pllvco, pllsource, pllr, pllm, sysclockfreq;  /* no init needed */

  if(__HAL_RCC_GET_PLL_OSCSOURCE() == RCC_PLLSOURCE_MSI)
  {
    /* Get MSI range source */
    if(READ_BIT(RCC->CR, RCC_CR_MSIRGSEL) == 0U)
    { /* MSISRANGE from RCC_CSR applies */
      msirange = READ_BIT(RCC->CSR, RCC_CSR_MSISRANGE) >> RCC_CSR_MSISRANGE_Pos;
    }
    else
    { /* MSIRANGE from RCC_CR applies */
      msirange = READ_BIT(RCC->CR, RCC_CR_MSIRANGE) >> RCC_CR_MSIRANGE_Pos;
    }
    /*MSI frequency range in HZ*/
    msirange = MSIRangeTable[msirange];
  }

  /* PLL_VCO = (HSE_VALUE or HSI_VALUE or MSI_VALUE) * PLLN / PLLM
     SYSCLK = PLL_VCO / PLLR
   */
  pllsource = READ_BIT(RCC->PLLCFGR, RCC_PLLCFGR_PLLSRC);

  switch (pllsource)
  {
  case RCC_PLLSOURCE_HSI:  /* HSI used as PLL clock source */
    pllvco = HSI_VALUE;
    break;

  case RCC_PLLSOURCE_HSE:  /* HSE used as PLL clock source */
    pllvco = HSE_VALUE;
    break;

  case RCC_PLLSOURCE_MSI:  /* MSI used as PLL clock source */
  default:
    pllvco = msirange;
    break;
  }
  pllm = (READ_BIT(RCC->PLLCFGR, RCC_PLLCFGR_PLLM) >> RCC_PLLCFGR_PLLM_Pos) + 1U ;
  pllvco = (pllvco * (READ_BIT(RCC->PLLCFGR, RCC_PLLCFGR_PLLN) >> RCC_PLLCFGR_PLLN_Pos)) / pllm;
  pllr = ((READ_BIT(RCC->PLLCFGR, RCC_PLLCFGR_PLLR) >> RCC_PLLCFGR_PLLR_Pos) + 1U ) * 2U;
  sysclockfreq = pllvco / pllr;

  return sysclockfreq;
}

RCC_SetFlashLatencyFromMSIRange()

static HAL_StatusTypeDef RCC_SetFlashLatencyFromMSIRange ( uint32_t  msirange )

static

Update number of Flash wait states in line with MSI range and current voltage range.

Parameters

msirange

MSI range value from RCC_MSIRANGE_0 to RCC_MSIRANGE_11

Return values

HAL

status

Definition at line 1716 of file stm32l4xx_hal_rcc.c.

{
  uint32_t vos;
  uint32_t latency = FLASH_LATENCY_0;  /* default value 0WS */

  if(__HAL_RCC_PWR_IS_CLK_ENABLED())
  {
    vos = HAL_PWREx_GetVoltageRange();
  }
  else
  {
    __HAL_RCC_PWR_CLK_ENABLE();
    vos = HAL_PWREx_GetVoltageRange();
    __HAL_RCC_PWR_CLK_DISABLE();
  }

  if(vos == PWR_REGULATOR_VOLTAGE_SCALE1)
  {
    if(msirange > RCC_MSIRANGE_8)
    {
      /* MSI > 16Mhz */
      if(msirange > RCC_MSIRANGE_10)
      {
        /* MSI 48Mhz */
        latency = FLASH_LATENCY_2; /* 2WS */
      }
      else
      {
        /* MSI 24Mhz or 32Mhz */
        latency = FLASH_LATENCY_1; /* 1WS */
      }
    }
    /* else MSI <= 16Mhz default FLASH_LATENCY_0 0WS */
  }
  else
  {
#if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
    if(msirange >= RCC_MSIRANGE_8)
    {
      /* MSI >= 16Mhz */
      latency = FLASH_LATENCY_2; /* 2WS */
    }
    else
    {
      if(msirange == RCC_MSIRANGE_7)
      {
        /* MSI 8Mhz */
        latency = FLASH_LATENCY_1; /* 1WS */
      }
      /* else MSI < 8Mhz default FLASH_LATENCY_0 0WS */
    }
#else
    if(msirange > RCC_MSIRANGE_8)
    {
      /* MSI > 16Mhz */
      latency = FLASH_LATENCY_3; /* 3WS */
    }
    else
    {
      if(msirange == RCC_MSIRANGE_8)
      {
        /* MSI 16Mhz */
        latency = FLASH_LATENCY_2; /* 2WS */
      }
      else if(msirange == RCC_MSIRANGE_7)
      {
        /* MSI 8Mhz */
        latency = FLASH_LATENCY_1; /* 1WS */
      }
      /* else MSI < 8Mhz default FLASH_LATENCY_0 0WS */
    }
#endif
  }

  __HAL_FLASH_SET_LATENCY(latency);

  /* Check that the new number of wait states is taken into account to access the Flash
     memory by reading the FLASH_ACR register */
  if(__HAL_FLASH_GET_LATENCY() != latency)
  {
    return HAL_ERROR;
  }

  return HAL_OK;
}