text: /**
    ******************************************************************************
    * @file    stm32l4xx_ll_utils.c
    * @author  MCD Application Team
    * @brief   UTILS LL module driver.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics.
    * All rights reserved.</center></h2>
    *
    * This software component is licensed by ST under BSD 3-Clause license,
    * the "License"; You may not use this file except in compliance with the
    * License. You may obtain a copy of the License at:
    *                        opensource.org/licenses/BSD-3-Clause
    *
    ******************************************************************************
    */
  /* Includes ------------------------------------------------------------------*/
  #include "stm32l4xx_ll_utils.h"
  #include "stm32l4xx_ll_rcc.h"
  #include "stm32l4xx_ll_system.h"
  #include "stm32l4xx_ll_pwr.h"
  #ifdef  USE_FULL_ASSERT
  #include "stm32_assert.h"
  #else
  #define assert_param(expr) ((void)0U)
  #endif /* USE_FULL_ASSERT */
  
  /** @addtogroup STM32L4xx_LL_Driver
    * @{
    */
  
  /** @addtogroup UTILS_LL
    * @{
    */
  
  /* Private types -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Private constants ---------------------------------------------------------*/
  /** @addtogroup UTILS_LL_Private_Constants
    * @{
    */
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
  #define UTILS_MAX_FREQUENCY_SCALE1  120000000U       /*!< Maximum frequency for system clock at power scale1, in Hz */
  #define UTILS_MAX_FREQUENCY_SCALE2   26000000U       /*!< Maximum frequency for system clock at power scale2, in Hz */
  #else
  #define UTILS_MAX_FREQUENCY_SCALE1   80000000U       /*!< Maximum frequency for system clock at power scale1, in Hz */
  #define UTILS_MAX_FREQUENCY_SCALE2   26000000U       /*!< Maximum frequency for system clock at power scale2, in Hz */
  #endif
  
  /* Defines used for PLL range */
  #define UTILS_PLLVCO_INPUT_MIN        4000000U       /*!< Frequency min for PLLVCO input, in Hz   */
  #define UTILS_PLLVCO_INPUT_MAX       16000000U       /*!< Frequency max for PLLVCO input, in Hz   */
  #define UTILS_PLLVCO_OUTPUT_MIN      64000000U       /*!< Frequency min for PLLVCO output, in Hz  */
  #define UTILS_PLLVCO_OUTPUT_MAX     344000000U       /*!< Frequency max for PLLVCO output, in Hz  */
  
  /* Defines used for HSE range */
  #define UTILS_HSE_FREQUENCY_MIN      4000000U        /*!< Frequency min for HSE frequency, in Hz   */
  #define UTILS_HSE_FREQUENCY_MAX     48000000U        /*!< Frequency max for HSE frequency, in Hz   */
  
  /* Defines used for FLASH latency according to HCLK Frequency */
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
  #define UTILS_SCALE1_LATENCY1_FREQ   20000000U       /*!< HCLK frequency to set FLASH latency 1 in power scale 1 */
  #define UTILS_SCALE1_LATENCY2_FREQ   40000000U       /*!< HCLK frequency to set FLASH latency 2 in power scale 1 */
  #define UTILS_SCALE1_LATENCY3_FREQ   60000000U       /*!< HCLK frequency to set FLASH latency 3 in power scale 1 */
  #define UTILS_SCALE1_LATENCY4_FREQ   80000000U       /*!< HCLK frequency to set FLASH latency 4 in power scale 1 */
  #define UTILS_SCALE1_LATENCY5_FREQ  100000000U       /*!< HCLK frequency to set FLASH latency 4 in power scale 1 */
  #define UTILS_SCALE2_LATENCY1_FREQ    8000000U       /*!< HCLK frequency to set FLASH latency 1 in power scale 2 */
  #define UTILS_SCALE2_LATENCY2_FREQ   16000000U       /*!< HCLK frequency to set FLASH latency 2 in power scale 2 */
  #else
  #define UTILS_SCALE1_LATENCY1_FREQ   16000000U       /*!< HCLK frequency to set FLASH latency 1 in power scale 1 */
  #define UTILS_SCALE1_LATENCY2_FREQ   32000000U       /*!< HCLK frequency to set FLASH latency 2 in power scale 1 */
  #define UTILS_SCALE1_LATENCY3_FREQ   48000000U       /*!< HCLK frequency to set FLASH latency 3 in power scale 1 */
  #define UTILS_SCALE1_LATENCY4_FREQ   64000000U       /*!< HCLK frequency to set FLASH latency 4 in power scale 1 */
  #define UTILS_SCALE2_LATENCY1_FREQ    6000000U       /*!< HCLK frequency to set FLASH latency 1 in power scale 2 */
  #define UTILS_SCALE2_LATENCY2_FREQ   12000000U       /*!< HCLK frequency to set FLASH latency 2 in power scale 2 */
  #define UTILS_SCALE2_LATENCY3_FREQ   18000000U       /*!< HCLK frequency to set FLASH latency 3 in power scale 2 */
  #endif
  /**
    * @}
    */
  
  /* Private macros ------------------------------------------------------------*/
  /** @addtogroup UTILS_LL_Private_Macros
    * @{
    */
  #define IS_LL_UTILS_SYSCLK_DIV(__VALUE__) (((__VALUE__) == LL_RCC_SYSCLK_DIV_1)   \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_2)   \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_4)   \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_8)   \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_16)  \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_64)  \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_128) \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_256) \
                                          || ((__VALUE__) == LL_RCC_SYSCLK_DIV_512))
  
  #define IS_LL_UTILS_APB1_DIV(__VALUE__) (((__VALUE__) == LL_RCC_APB1_DIV_1) \
                                        || ((__VALUE__) == LL_RCC_APB1_DIV_2) \
                                        || ((__VALUE__) == LL_RCC_APB1_DIV_4) \
                                        || ((__VALUE__) == LL_RCC_APB1_DIV_8) \
                                        || ((__VALUE__) == LL_RCC_APB1_DIV_16))
  
  #define IS_LL_UTILS_APB2_DIV(__VALUE__) (((__VALUE__) == LL_RCC_APB2_DIV_1) \
                                        || ((__VALUE__) == LL_RCC_APB2_DIV_2) \
                                        || ((__VALUE__) == LL_RCC_APB2_DIV_4) \
                                        || ((__VALUE__) == LL_RCC_APB2_DIV_8) \
                                        || ((__VALUE__) == LL_RCC_APB2_DIV_16))
  
  #define IS_LL_UTILS_PLLM_VALUE(__VALUE__) (((__VALUE__) == LL_RCC_PLLM_DIV_1) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_2) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_3) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_4) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_5) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_6) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_7) \
                                          || ((__VALUE__) == LL_RCC_PLLM_DIV_8))
  
  #define IS_LL_UTILS_PLLN_VALUE(__VALUE__) ((8U <= (__VALUE__)) && ((__VALUE__) <= 86U))
  
  #define IS_LL_UTILS_PLLR_VALUE(__VALUE__) (((__VALUE__) == LL_RCC_PLLR_DIV_2) \
                                          || ((__VALUE__) == LL_RCC_PLLR_DIV_4) \
                                          || ((__VALUE__) == LL_RCC_PLLR_DIV_6) \
                                          || ((__VALUE__) == LL_RCC_PLLR_DIV_8))
  
  #define IS_LL_UTILS_PLLVCO_INPUT(__VALUE__)  ((UTILS_PLLVCO_INPUT_MIN <= (__VALUE__)) && ((__VALUE__) <= UTILS_PLLVCO_INPUT_MAX))
  
  #define IS_LL_UTILS_PLLVCO_OUTPUT(__VALUE__) ((UTILS_PLLVCO_OUTPUT_MIN <= (__VALUE__)) && ((__VALUE__) <= UTILS_PLLVCO_OUTPUT_MAX))
  
  #define IS_LL_UTILS_PLL_FREQUENCY(__VALUE__) ((LL_PWR_GetRegulVoltageScaling() == LL_PWR_REGU_VOLTAGE_SCALE1) ? ((__VALUE__) <= UTILS_MAX_FREQUENCY_SCALE1) : \
                                               ((__VALUE__) <= UTILS_MAX_FREQUENCY_SCALE2))
  
  #define IS_LL_UTILS_HSE_BYPASS(__STATE__) (((__STATE__) == LL_UTILS_HSEBYPASS_ON) \
                                          || ((__STATE__) == LL_UTILS_HSEBYPASS_OFF))
  
  #define IS_LL_UTILS_HSE_FREQUENCY(__FREQUENCY__) (((__FREQUENCY__) >= UTILS_HSE_FREQUENCY_MIN) && ((__FREQUENCY__) <= UTILS_HSE_FREQUENCY_MAX))
  /**
    * @}
    */
  /* Private function prototypes -----------------------------------------------*/
  /** @defgroup UTILS_LL_Private_Functions UTILS Private functions
    * @{
    */
  static uint32_t    UTILS_GetPLLOutputFrequency(uint32_t PLL_InputFrequency,
                                                 LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct);
  static ErrorStatus UTILS_SetFlashLatency(uint32_t HCLK_Frequency);
  static ErrorStatus UTILS_EnablePLLAndSwitchSystem(uint32_t SYSCLK_Frequency, LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct);
  static ErrorStatus UTILS_PLL_IsBusy(void);
  /**
    * @}
    */
  
  /* Exported functions --------------------------------------------------------*/
  /** @addtogroup UTILS_LL_Exported_Functions
    * @{
    */
  
  /** @addtogroup UTILS_LL_EF_DELAY
    * @{
    */
  
  /**
    * @brief  This function configures the Cortex-M SysTick source to have 1ms time base.
    * @note   When a RTOS is used, it is recommended to avoid changing the Systick
    *         configuration by calling this function, for a delay use rather osDelay RTOS service.
    * @param  HCLKFrequency HCLK frequency in Hz
    * @note   HCLK frequency can be calculated thanks to RCC helper macro or function @ref LL_RCC_GetSystemClocksFreq
    * @retval None
    */
  void LL_Init1msTick(uint32_t HCLKFrequency)
  {
    /* Use frequency provided in argument */
    LL_InitTick(HCLKFrequency, 1000U);
  }
  
  /**
    * @brief  This function provides accurate delay (in milliseconds) based
    *         on SysTick counter flag
    * @note   When a RTOS is used, it is recommended to avoid using blocking delay
    *         and use rather osDelay service.
    * @note   To respect 1ms timebase, user should call @ref LL_Init1msTick function which
    *         will configure Systick to 1ms
    * @param  Delay specifies the delay time length, in milliseconds.
    * @retval None
    */
  void LL_mDelay(uint32_t Delay)
  {
    __IO uint32_t  tmp = SysTick->CTRL;  /* Clear the COUNTFLAG first */
    uint32_t tmpDelay = Delay;
  
    /* Add this code to indicate that local variable is not used */
    ((void)tmp);
  
    /* Add a period to guaranty minimum wait */
    if(tmpDelay < LL_MAX_DELAY)
    {
      tmpDelay++;
    }
  
    while (tmpDelay != 0U)
    {
      if((SysTick->CTRL & SysTick_CTRL_COUNTFLAG_Msk) != 0U)
      {
        tmpDelay--;
      }
    }
  }
  
  /**
    * @}
    */
  
  /** @addtogroup UTILS_EF_SYSTEM
    *  @brief    System Configuration functions
    *
    @verbatim
   ===============================================================================
             ##### System Configuration functions #####
   ===============================================================================
      [..]
           System, AHB and APB buses clocks configuration
  
           (+) The maximum frequency of the SYSCLK, HCLK, PCLK1 and PCLK2 is
               120000000 Hz for STM32L4Rx/STM32L4Sx devices and 80000000 Hz for others.
    @endverbatim
    @internal
               Depending on the device voltage range, the maximum frequency should be
               adapted accordingly:
  
               (++) Table 1. HCLK clock frequency for STM32L4Rx/STM32L4Sx devices
               (++) +--------------------------------------------------------+
               (++) | Latency         |     HCLK clock frequency (MHz)       |
               (++) |                 |--------------------------------------|
               (++) |                 |  voltage range 1  | voltage range 2  |
               (++) |                 |       1.2 V       |     1.0 V        |
               (++) |-----------------|-------------------|------------------|
               (++) |0WS(1 CPU cycles)|   0 < HCLK <= 20  |  0 < HCLK <= 8   |
               (++) |-----------------|-------------------|------------------|
               (++) |1WS(2 CPU cycles)|  20 < HCLK <= 40  |  8 < HCLK <= 16  |
               (++) |-----------------|-------------------|------------------|
               (++) |2WS(3 CPU cycles)|  40 < HCLK <= 60  | 16 < HCLK <= 26  |
               (++) |-----------------|-------------------|------------------|
               (++) |3WS(4 CPU cycles)|  60 < HCLK <= 80  | 16 < HCLK <= 26  |
               (++) |-----------------|-------------------|------------------|
               (++) |4WS(5 CPU cycles)|  80 < HCLK <= 100 | 16 < HCLK <= 26  |
               (++) |-----------------|-------------------|------------------|
               (++) |5WS(6 CPU cycles)| 100 < HCLK <= 120 | 16 < HCLK <= 26  |
               (++) +--------------------------------------------------------+
  
               (++) Table 2. HCLK clock frequency for other STM32L4 devices
               (++) +-------------------------------------------------------+
               (++) | Latency         |    HCLK clock frequency (MHz)       |
               (++) |                 |-------------------------------------|
               (++) |                 | voltage range 1  | voltage range 2  |
               (++) |                 |      1.2 V       |     1.0 V        |
               (++) |-----------------|------------------|------------------|
               (++) |0WS(1 CPU cycles)|  0 < HCLK <= 16  |  0 < HCLK <= 6   |
               (++) |-----------------|------------------|------------------|
               (++) |1WS(2 CPU cycles)| 16 < HCLK <= 32  |  6 < HCLK <= 12  |
               (++) |-----------------|------------------|------------------|
               (++) |2WS(3 CPU cycles)| 32 < HCLK <= 48  | 12 < HCLK <= 18  |
               (++) |-----------------|------------------|------------------|
               (++) |3WS(4 CPU cycles)| 48 < HCLK <= 64  | 18 < HCLK <= 26  |
               (++) |-----------------|------------------|------------------|
               (++) |4WS(5 CPU cycles)| 64 < HCLK <= 80  | 18 < HCLK <= 26  |
               (++) +-------------------------------------------------------+
  
    @endinternal
    * @{
    */
  
  /**
    * @brief  This function sets directly SystemCoreClock CMSIS variable.
    * @note   Variable can be calculated also through SystemCoreClockUpdate function.
    * @param  HCLKFrequency HCLK frequency in Hz (can be calculated thanks to RCC helper macro)
    * @retval None
    */
  void LL_SetSystemCoreClock(uint32_t HCLKFrequency)
  {
    /* HCLK clock frequency */
    SystemCoreClock = HCLKFrequency;
  }
  
  /**
    * @brief  This function configures system clock with MSI as clock source of the PLL
    * @note   The application needs to ensure that PLL, PLLSAI1 and/or PLLSAI2 are disabled.
    * @note   Function is based on the following formula:
    *         - PLL output frequency = (((MSI frequency / PLLM) * PLLN) / PLLR)
    *         - PLLM: ensure that the VCO input frequency ranges from 4 to 16 MHz (PLLVCO_input = MSI frequency / PLLM)
    *         - PLLN: ensure that the VCO output frequency is between 64 and 344 MHz (PLLVCO_output = PLLVCO_input * PLLN)
    *         - PLLR: ensure that max frequency at 120000000 Hz is reached (PLLVCO_output / PLLR)
    * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
    *                             the configuration information for the PLL.
    * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
    *                             the configuration information for the BUS prescalers.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: Max frequency configuration done
    *          - ERROR: Max frequency configuration not done
    */
  ErrorStatus LL_PLL_ConfigSystemClock_MSI(LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct,
                                           LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
  {
    ErrorStatus status = SUCCESS;
    uint32_t pllfreq, msi_range;
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
    uint32_t hpre = 0U;  /* Set default value */
  #endif
  
    /* Check if one of the PLL is enabled */
    if(UTILS_PLL_IsBusy() == SUCCESS)
    {
      /* Get the current MSI range */
      if(LL_RCC_MSI_IsEnabledRangeSelect() != 0U)
      {
        msi_range =  LL_RCC_MSI_GetRange();
        switch (msi_range)
        {
          case LL_RCC_MSIRANGE_0:     /* MSI = 100 KHz  */
          case LL_RCC_MSIRANGE_1:     /* MSI = 200 KHz  */
          case LL_RCC_MSIRANGE_2:     /* MSI = 400 KHz  */
          case LL_RCC_MSIRANGE_3:     /* MSI = 800 KHz  */
          case LL_RCC_MSIRANGE_4:     /* MSI = 1 MHz    */
          case LL_RCC_MSIRANGE_5:     /* MSI = 2 MHz    */
            /* PLLVCO input frequency is not in the range from 4 to 16 MHz*/
            status = ERROR;
            break;
  
          case LL_RCC_MSIRANGE_6:     /* MSI = 4 MHz    */
          case LL_RCC_MSIRANGE_7:     /* MSI = 8 MHz    */
          case LL_RCC_MSIRANGE_8:     /* MSI = 16 MHz   */
          case LL_RCC_MSIRANGE_9:     /* MSI = 24 MHz   */
          case LL_RCC_MSIRANGE_10:    /* MSI = 32 MHz   */
          case LL_RCC_MSIRANGE_11:    /* MSI = 48 MHz   */
          default:
            break;
        }
      }
      else
      {
        msi_range = LL_RCC_MSI_GetRangeAfterStandby();
        switch (msi_range)
        {
          case LL_RCC_MSISRANGE_4:    /* MSI = 1 MHz    */
          case LL_RCC_MSISRANGE_5:    /* MSI = 2 MHz    */
            /* PLLVCO input frequency is not in the range from 4 to 16 MHz*/
            status = ERROR;
            break;
  
          case LL_RCC_MSISRANGE_7:    /* MSI = 8 MHz    */
          case LL_RCC_MSISRANGE_6:    /* MSI = 4 MHz    */
          default:
            break;
        }
      }
  
      /* Main PLL configuration and activation */
      if(status != ERROR)
      {
        /* Calculate the new PLL output frequency */
        pllfreq = UTILS_GetPLLOutputFrequency(__LL_RCC_CALC_MSI_FREQ(LL_RCC_MSI_IsEnabledRangeSelect(), msi_range),
                                              UTILS_PLLInitStruct);
  
        /* Enable MSI if not enabled */
        if(LL_RCC_MSI_IsReady() != 1U)
        {
          LL_RCC_MSI_Enable();
          while ((LL_RCC_MSI_IsReady() != 1U))
          {
            /* Wait for MSI ready */
          }
        }
  
        /* Configure PLL */
        LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_MSI, UTILS_PLLInitStruct->PLLM, UTILS_PLLInitStruct->PLLN,
                                    UTILS_PLLInitStruct->PLLR);
  
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
        /* Prevent undershoot at highest frequency by applying intermediate AHB prescaler 2 */
        if(pllfreq > 80000000U)
        {
          hpre = UTILS_ClkInitStruct->AHBCLKDivider;
          if(hpre == LL_RCC_SYSCLK_DIV_1)
          {
            UTILS_ClkInitStruct->AHBCLKDivider = LL_RCC_SYSCLK_DIV_2;
          }
        }
  #endif
        /* Enable PLL and switch system clock to PLL */
        status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
        /* Apply definitive AHB prescaler value if necessary */
        if((status == SUCCESS) && (hpre != 0U))
        {
          UTILS_ClkInitStruct->AHBCLKDivider = LL_RCC_SYSCLK_DIV_1;
          LL_RCC_SetAHBPrescaler(UTILS_ClkInitStruct->AHBCLKDivider);
        }
  #endif
      }
    }
    else
    {
      /* Current PLL configuration cannot be modified */
      status = ERROR;
    }
  
    return status;
  }
  
  /**
    * @brief  This function configures system clock at maximum frequency with HSI as clock source of the PLL
    * @note   The application need to ensure that PLL, PLLSAI1 and/or PLLSAI2 are disabled.
    * @note   Function is based on the following formula:
    *         - PLL output frequency = (((HSI frequency / PLLM) * PLLN) / PLLR)
    *         - PLLM: ensure that the VCO input frequency ranges from 4 to 16 MHz (PLLVCO_input = HSI frequency / PLLM)
    *         - PLLN: ensure that the VCO output frequency is between 64 and 344 MHz (PLLVCO_output = PLLVCO_input * PLLN)
    *         - PLLR: ensure that max frequency at 120000000 Hz is reach (PLLVCO_output / PLLR)
    * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
    *                             the configuration information for the PLL.
    * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
    *                             the configuration information for the BUS prescalers.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: Max frequency configuration done
    *          - ERROR: Max frequency configuration not done
    */
  ErrorStatus LL_PLL_ConfigSystemClock_HSI(LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct,
                                           LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
  {
    ErrorStatus status;
    uint32_t pllfreq;
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
    uint32_t hpre = 0U;  /* Set default value */
  #endif
  
    /* Check if one of the PLL is enabled */
    if(UTILS_PLL_IsBusy() == SUCCESS)
    {
      /* Calculate the new PLL output frequency */
      pllfreq = UTILS_GetPLLOutputFrequency(HSI_VALUE, UTILS_PLLInitStruct);
  
      /* Enable HSI if not enabled */
      if(LL_RCC_HSI_IsReady() != 1U)
      {
        LL_RCC_HSI_Enable();
        while (LL_RCC_HSI_IsReady() != 1U)
        {
          /* Wait for HSI ready */
        }
      }
  
      /* Configure PLL */
      LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSI, UTILS_PLLInitStruct->PLLM, UTILS_PLLInitStruct->PLLN,
                                  UTILS_PLLInitStruct->PLLR);
  
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
      /* Prevent undershoot at highest frequency by applying intermediate AHB prescaler 2 */
      if(pllfreq > 80000000U)
      {
        hpre = UTILS_ClkInitStruct->AHBCLKDivider;
        if(hpre == LL_RCC_SYSCLK_DIV_1)
        {
          UTILS_ClkInitStruct->AHBCLKDivider = LL_RCC_SYSCLK_DIV_2;
        }
      }
  #endif
      /* Enable PLL and switch system clock to PLL */
      status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
      /* Apply definitive AHB prescaler value if necessary */
      if((status == SUCCESS) && (hpre != 0U))
      {
        UTILS_ClkInitStruct->AHBCLKDivider = LL_RCC_SYSCLK_DIV_1;
        LL_RCC_SetAHBPrescaler(UTILS_ClkInitStruct->AHBCLKDivider);
      }
  #endif
    }
    else
    {
      /* Current PLL configuration cannot be modified */
      status = ERROR;
    }
  
    return status;
  }
  
  /**
    * @brief  This function configures system clock with HSE as clock source of the PLL
    * @note   The application need to ensure that PLL, PLLSAI1 and/or PLLSAI2 are disabled.
    * @note   Function is based on the following formula:
    *         - PLL output frequency = (((HSE frequency / PLLM) * PLLN) / PLLR)
    *         - PLLM: ensure that the VCO input frequency ranges from 4 to 16 MHz (PLLVCO_input = HSE frequency / PLLM)
    *         - PLLN: ensure that the VCO output frequency is between 64 and 344 MHz (PLLVCO_output = PLLVCO_input * PLLN)
    *         - PLLR: ensure that max frequency at 120000000 Hz is reached (PLLVCO_output / PLLR)
    * @param  HSEFrequency Value between Min_Data = 4000000 and Max_Data = 48000000
    * @param  HSEBypass This parameter can be one of the following values:
    *         @arg @ref LL_UTILS_HSEBYPASS_ON
    *         @arg @ref LL_UTILS_HSEBYPASS_OFF
    * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
    *                             the configuration information for the PLL.
    * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
    *                             the configuration information for the BUS prescalers.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: Max frequency configuration done
    *          - ERROR: Max frequency configuration not done
    */
  ErrorStatus LL_PLL_ConfigSystemClock_HSE(uint32_t HSEFrequency, uint32_t HSEBypass,
                                           LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct, LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
  {
    ErrorStatus status;
    uint32_t pllfreq;
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
    uint32_t hpre = 0U;  /* Set default value */
  #endif
  
    /* Check the parameters */
    assert_param(IS_LL_UTILS_HSE_FREQUENCY(HSEFrequency));
    assert_param(IS_LL_UTILS_HSE_BYPASS(HSEBypass));
  
    /* Check if one of the PLL is enabled */
    if(UTILS_PLL_IsBusy() == SUCCESS)
    {
      /* Calculate the new PLL output frequency */
      pllfreq = UTILS_GetPLLOutputFrequency(HSEFrequency, UTILS_PLLInitStruct);
  
      /* Enable HSE if not enabled */
      if(LL_RCC_HSE_IsReady() != 1U)
      {
        /* Check if need to enable HSE bypass feature or not */
        if(HSEBypass == LL_UTILS_HSEBYPASS_ON)
        {
          LL_RCC_HSE_EnableBypass();
        }
        else
        {
          LL_RCC_HSE_DisableBypass();
        }
  
        /* Enable HSE */
        LL_RCC_HSE_Enable();
        while (LL_RCC_HSE_IsReady() != 1U)
        {
          /* Wait for HSE ready */
        }
      }
  
      /* Configure PLL */
      LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE, UTILS_PLLInitStruct->PLLM, UTILS_PLLInitStruct->PLLN,
                                  UTILS_PLLInitStruct->PLLR);
  
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
      /* Prevent undershoot at highest frequency by applying intermediate AHB prescaler 2 */
      if(pllfreq > 80000000U)
      {
        hpre = UTILS_ClkInitStruct->AHBCLKDivider;
        if(hpre == LL_RCC_SYSCLK_DIV_1)
        {
          UTILS_ClkInitStruct->AHBCLKDivider = LL_RCC_SYSCLK_DIV_2;
        }
      }
  #endif
      /* Enable PLL and switch system clock to PLL */
      status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
      /* Apply definitive AHB prescaler value if necessary */
      if((status == SUCCESS) && (hpre != 0U))
      {
        UTILS_ClkInitStruct->AHBCLKDivider = LL_RCC_SYSCLK_DIV_1;
        LL_RCC_SetAHBPrescaler(UTILS_ClkInitStruct->AHBCLKDivider);
      }
  #endif
    }
    else
    {
      /* Current PLL configuration cannot be modified */
      status = ERROR;
    }
  
    return status;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /** @addtogroup UTILS_LL_Private_Functions
    * @{
    */
  /**
    * @brief  Update number of Flash wait states in line with new frequency and current
              voltage range.
    * @param  HCLK_Frequency  HCLK frequency
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: Latency has been modified
    *          - ERROR: Latency cannot be modified
    */
  static ErrorStatus UTILS_SetFlashLatency(uint32_t HCLK_Frequency)
  {
    ErrorStatus status = SUCCESS;
  
    uint32_t latency = LL_FLASH_LATENCY_0;  /* default value 0WS */
  
    /* Frequency cannot be equal to 0 */
    if(HCLK_Frequency == 0U)
    {
      status = ERROR;
    }
    else
    {
      if(LL_PWR_GetRegulVoltageScaling() == LL_PWR_REGU_VOLTAGE_SCALE1)
      {
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
        if(HCLK_Frequency > UTILS_SCALE1_LATENCY5_FREQ)
        {
          /* 100 < HCLK <= 120 => 5WS (6 CPU cycles) */
          latency = LL_FLASH_LATENCY_5;
        }
        else if(HCLK_Frequency > UTILS_SCALE1_LATENCY4_FREQ)
        {
          /* 80 < HCLK <= 100 => 4WS (5 CPU cycles) */
          latency = LL_FLASH_LATENCY_4;
        }
        else if(HCLK_Frequency > UTILS_SCALE1_LATENCY3_FREQ)
        {
          /* 60 < HCLK <= 80 => 3WS (4 CPU cycles) */
          latency = LL_FLASH_LATENCY_3;
        }
        else if(HCLK_Frequency > UTILS_SCALE1_LATENCY2_FREQ)
        {
          /* 40 < HCLK <= 20 => 2WS (3 CPU cycles) */
          latency = LL_FLASH_LATENCY_2;
        }
        else
        {
          if(HCLK_Frequency > UTILS_SCALE1_LATENCY1_FREQ)
          {
            /* 20 < HCLK <= 40 => 1WS (2 CPU cycles) */
            latency = LL_FLASH_LATENCY_1;
          }
          /* else HCLK_Frequency <= 10MHz default LL_FLASH_LATENCY_0 0WS */
        }
  #else
        if(HCLK_Frequency > UTILS_SCALE1_LATENCY4_FREQ)
        {
          /* 64 < HCLK <= 80 => 4WS (5 CPU cycles) */
          latency = LL_FLASH_LATENCY_4;
        }
        else if(HCLK_Frequency > UTILS_SCALE1_LATENCY3_FREQ)
        {
          /* 48 < HCLK <= 64 => 3WS (4 CPU cycles) */
          latency = LL_FLASH_LATENCY_3;
        }
        else if(HCLK_Frequency > UTILS_SCALE1_LATENCY2_FREQ)
        {
          /* 32 < HCLK <= 48 => 2WS (3 CPU cycles) */
          latency = LL_FLASH_LATENCY_2;
        }
        else
        {
          if(HCLK_Frequency > UTILS_SCALE1_LATENCY1_FREQ)
          {
            /* 16 < HCLK <= 32 => 1WS (2 CPU cycles) */
            latency = LL_FLASH_LATENCY_1;
          }
          /* else HCLK_Frequency <= 16MHz default LL_FLASH_LATENCY_0 0WS */
        }
  #endif
      }
      else /* SCALE2 */
      {
  #if defined(STM32L4R5xx) || defined(STM32L4R7xx) || defined(STM32L4R9xx) || defined(STM32L4S5xx) || defined(STM32L4S7xx) || defined(STM32L4S9xx)
        if(HCLK_Frequency > UTILS_SCALE2_LATENCY2_FREQ)
        {
          /* 16 < HCLK <= 26 => 2WS (3 CPU cycles) */
          latency = LL_FLASH_LATENCY_2;
        }
        else
        {
          if(HCLK_Frequency > UTILS_SCALE2_LATENCY1_FREQ)
          {
            /* 8 < HCLK <= 16 => 1WS (2 CPU cycles) */
            latency = LL_FLASH_LATENCY_1;
          }
          /* else HCLK_Frequency <= 8MHz default LL_FLASH_LATENCY_0 0WS */
        }
  #else
        if(HCLK_Frequency > UTILS_SCALE2_LATENCY3_FREQ)
        {
          /* 18 < HCLK <= 26 => 3WS (4 CPU cycles) */
          latency = LL_FLASH_LATENCY_3;
        }
        else if(HCLK_Frequency > UTILS_SCALE2_LATENCY2_FREQ)
        {
          /* 12 < HCLK <= 18 => 2WS (3 CPU cycles) */
          latency = LL_FLASH_LATENCY_2;
        }
        else
        {
          if(HCLK_Frequency > UTILS_SCALE2_LATENCY1_FREQ)
          {
            /* 6 < HCLK <= 12 => 1WS (2 CPU cycles) */
            latency = LL_FLASH_LATENCY_1;
          }
          /* else HCLK_Frequency <= 6MHz default LL_FLASH_LATENCY_0 0WS */
        }
  #endif
      }
  
      LL_FLASH_SetLatency(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(LL_FLASH_GetLatency() != latency)
      {
        status = ERROR;
      }
    }
    return status;
  }
  
  /**
    * @brief  Function to check that PLL can be modified
    * @param  PLL_InputFrequency  PLL input frequency (in Hz)
    * @param  UTILS_PLLInitStruct pointer to a @ref LL_UTILS_PLLInitTypeDef structure that contains
    *                             the configuration information for the PLL.
    * @retval PLL output frequency (in Hz)
    */
  static uint32_t UTILS_GetPLLOutputFrequency(uint32_t PLL_InputFrequency, LL_UTILS_PLLInitTypeDef *UTILS_PLLInitStruct)
  {
    uint32_t pllfreq;
  
    /* Check the parameters */
    assert_param(IS_LL_UTILS_PLLM_VALUE(UTILS_PLLInitStruct->PLLM));
    assert_param(IS_LL_UTILS_PLLN_VALUE(UTILS_PLLInitStruct->PLLN));
    assert_param(IS_LL_UTILS_PLLR_VALUE(UTILS_PLLInitStruct->PLLR));
  
    /* Check different PLL parameters according to RM                          */
    /*  - PLLM: ensure that the VCO input frequency ranges from 4 to 16 MHz.   */
    pllfreq = PLL_InputFrequency / (((UTILS_PLLInitStruct->PLLM >> RCC_PLLCFGR_PLLM_Pos) + 1U));
    assert_param(IS_LL_UTILS_PLLVCO_INPUT(pllfreq));
  
    /*  - PLLN: ensure that the VCO output frequency is between 64 and 344 MHz.*/
    pllfreq = pllfreq * (UTILS_PLLInitStruct->PLLN & (RCC_PLLCFGR_PLLN >> RCC_PLLCFGR_PLLN_Pos));
    assert_param(IS_LL_UTILS_PLLVCO_OUTPUT(pllfreq));
  
    /*  - PLLR: ensure that max frequency at 120000000 Hz is reached                   */
    pllfreq = pllfreq / (((UTILS_PLLInitStruct->PLLR >> RCC_PLLCFGR_PLLR_Pos) + 1U) * 2U);
    assert_param(IS_LL_UTILS_PLL_FREQUENCY(pllfreq));
  
    return pllfreq;
  }
  
  /**
    * @brief  Function to check that PLL can be modified
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: PLL modification can be done
    *          - ERROR: PLL is busy
    */
  static ErrorStatus UTILS_PLL_IsBusy(void)
  {
    ErrorStatus status = SUCCESS;
  
    /* Check if PLL is busy*/
    if(LL_RCC_PLL_IsReady() != 0U)
    {
      /* PLL configuration cannot be modified */
      status = ERROR;
    }
  
  #if defined(RCC_PLLSAI1_SUPPORT)
    /* Check if PLLSAI1 is busy*/
    if(LL_RCC_PLLSAI1_IsReady() != 0U)
    {
      /* PLLSAI1 configuration cannot be modified */
      status = ERROR;
    }
  #endif /*RCC_PLLSAI1_SUPPORT*/
  #if defined(RCC_PLLSAI2_SUPPORT)
  
    /* Check if PLLSAI2 is busy*/
    if(LL_RCC_PLLSAI2_IsReady() != 0U)
    {
      /* PLLSAI2 configuration cannot be modified */
      status = ERROR;
    }
  #endif /*RCC_PLLSAI2_SUPPORT*/
  
    return status;
  }
  
  /**
    * @brief  Function to enable PLL and switch system clock to PLL
    * @param  SYSCLK_Frequency SYSCLK frequency
    * @param  UTILS_ClkInitStruct pointer to a @ref LL_UTILS_ClkInitTypeDef structure that contains
    *                             the configuration information for the BUS prescalers.
    * @retval An ErrorStatus enumeration value:
    *          - SUCCESS: No problem to switch system to PLL
    *          - ERROR: Problem to switch system to PLL
    */
  static ErrorStatus UTILS_EnablePLLAndSwitchSystem(uint32_t SYSCLK_Frequency, LL_UTILS_ClkInitTypeDef *UTILS_ClkInitStruct)
  {
    ErrorStatus status = SUCCESS;
    uint32_t hclk_frequency;
  
    assert_param(IS_LL_UTILS_SYSCLK_DIV(UTILS_ClkInitStruct->AHBCLKDivider));
    assert_param(IS_LL_UTILS_APB1_DIV(UTILS_ClkInitStruct->APB1CLKDivider));
    assert_param(IS_LL_UTILS_APB2_DIV(UTILS_ClkInitStruct->APB2CLKDivider));
  
    /* Calculate HCLK frequency */
    hclk_frequency = __LL_RCC_CALC_HCLK_FREQ(SYSCLK_Frequency, UTILS_ClkInitStruct->AHBCLKDivider);
  
    /* Increasing the number of wait states because of higher CPU frequency */
    if(SystemCoreClock < hclk_frequency)
    {
      /* Set FLASH latency to highest latency */
      status = UTILS_SetFlashLatency(hclk_frequency);
    }
  
    /* Update system clock configuration */
    if(status == SUCCESS)
    {
      /* Enable PLL */
      LL_RCC_PLL_Enable();
      LL_RCC_PLL_EnableDomain_SYS();
      while (LL_RCC_PLL_IsReady() != 1U)
      {
        /* Wait for PLL ready */
      }
  
      /* Sysclk activation on the main PLL */
      LL_RCC_SetAHBPrescaler(UTILS_ClkInitStruct->AHBCLKDivider);
      LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
      while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
      {
        /* Wait for system clock switch to PLL */
      }
  
      /* Set APB1 & APB2 prescaler*/
      LL_RCC_SetAPB1Prescaler(UTILS_ClkInitStruct->APB1CLKDivider);
      LL_RCC_SetAPB2Prescaler(UTILS_ClkInitStruct->APB2CLKDivider);
    }
  
    /* Decreasing the number of wait states because of lower CPU frequency */
    if(SystemCoreClock > hclk_frequency)
    {
      /* Set FLASH latency to lowest latency */
      status = UTILS_SetFlashLatency(hclk_frequency);
    }
  
    /* Update SystemCoreClock variable */
    if(status == SUCCESS)
    {
      LL_SetSystemCoreClock(hclk_frequency);
    }
  
    return status;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  