stm32g0xx_ll_utils.c

/**
  ******************************************************************************
  * @file    stm32g0xx_ll_utils.c
  * @author  MCD Application Team
  * @brief   UTILS LL module driver.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2018 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 "stm32g0xx_ll_utils.h"
#include "stm32g0xx_ll_rcc.h"
#include "stm32g0xx_ll_system.h"
#include "stm32g0xx_ll_pwr.h"
#ifdef  USE_FULL_ASSERT
#include "stm32_assert.h"
#else
#define assert_param(expr) ((void)0U)
#endif /* USE_FULL_ASSERT */

/** @addtogroup STM32G0xx_LL_Driver
  * @{
  */

/** @addtogroup UTILS_LL
  * @{
  */

/* Private types -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private constants ---------------------------------------------------------*/
/** @addtogroup UTILS_LL_Private_Constants
  * @{
  */
#define UTILS_MAX_FREQUENCY          64000000U     /*!< Maximum frequency for system clock, in Hz */

/* Defines used for PLL range */
#define UTILS_PLLVCO_INPUT_MIN       4000000U      /*!< Frequency min for PLLVCO input, in Hz   */
#define UTILS_PLLVCO_INPUT_MAX       8000000U      /*!< 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 */
#define UTILS_SCALE1_LATENCY1_FREQ  24000000U       /*!< HCLK frequency to set FLASH latency 1 in power scale 1  */
#define UTILS_SCALE1_LATENCY2_FREQ  48000000U       /*!< HCLK frequency to set FLASH latency 2 in power scale 1  */
#define UTILS_SCALE1_LATENCY3_FREQ  64000000U       /*!< HCLK frequency to set FLASH latency 3 in power scale 1  */
/**
  * @}
  */

/* 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_HSI_DIV(__VALUE__)  (((__VALUE__) == LL_RCC_HSI_DIV_1)  \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_2)  \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_4)  \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_8)  \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_16) \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_32) \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_64) \
                                      || ((__VALUE__) == LL_RCC_HSI_DIV_128))

#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_3) \
                                        || ((__VALUE__) == LL_RCC_PLLR_DIV_4) \
                                        || ((__VALUE__) == LL_RCC_PLLR_DIV_5) \
                                        || ((__VALUE__) == LL_RCC_PLLR_DIV_6) \
                                        || ((__VALUE__) == LL_RCC_PLLR_DIV_7) \
                                        || ((__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__) ((__VALUE__) <= UTILS_MAX_FREQUENCY)

#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_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; /* MISRAC2012-Rule-17.8 */
  /* Add this code to indicate that local variable is not used */
  ((void)tmp);
  tmpDelay  = Delay;
  /* 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 is 64000000 Hz.
  @endverbatim
  @internal
             Depending on the device voltage range, the maximum frequency should be
             adapted accordingly:

             (++)  Table 1. HCLK clock frequency.
             (++)  +-------------------------------------------------------+
             (++)  | Latency         |    HCLK clock frequency (MHz)       |
             (++)  |                 |-------------------------------------|
             (++)  |                 | voltage range 1  | voltage range 2  |
             (++)  |                 |   1.08V - 1.32V  |  0.9 V - 1.10V   |
             (++)  |-----------------|------------------|------------------|
             (++)  |0WS(1 CPU cycles)|      HCLK <= 24  |      HCLK <= 8   |
             (++)  |-----------------|------------------|------------------|
             (++)  |1WS(2 CPU cycles)|      HCLK <= 48  |      HCLK <= 16  |
             (++)  |-----------------|------------------|------------------|
             (++)  |2WS(3 CPU cycles)|      HCLK <= 64  |        -         |
             (++)  |-----------------|------------------|------------------|

  @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 at maximum frequency with HSI as clock source of the PLL
  * @note   The application need to ensure that PLL is 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 64000000 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;

  /* 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);

    /* Enable PLL and switch system clock to PLL */
    status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  }
  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 is 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 64000000 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;

  /* 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);

    /* Enable PLL and switch system clock to PLL */
    status = UTILS_EnablePLLAndSwitchSystem(pllfreq, UTILS_ClkInitStruct);
  }
  else
  {
    /* Current PLL configuration cannot be modified */
    status = ERROR;
  }

  return status;
}

/**
  * @brief  Update number of Flash wait states in line with new frequency and current
  *         voltage range.
  * @param  HCLKFrequency  HCLK frequency
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: Latency has been modified
  *          - ERROR: Latency cannot be modified
  */
ErrorStatus LL_SetFlashLatency(uint32_t HCLKFrequency)
{
  uint32_t timeout;
  uint32_t getlatency;
  uint32_t latency;
  ErrorStatus status;

  /* Frequency cannot be equal to 0 or greater than max clock */
  if ((HCLKFrequency == 0U) || (HCLKFrequency > UTILS_SCALE1_LATENCY3_FREQ))
  {
    status = ERROR;
  }
  else
  {
    if (HCLKFrequency > UTILS_SCALE1_LATENCY2_FREQ)
    {
      /* 48 < HCLK <= 64 => 2WS (3 CPU cycles) */
      latency = LL_FLASH_LATENCY_2;
    }
    else
    {
      if (HCLKFrequency > UTILS_SCALE1_LATENCY1_FREQ)
      {
        /* 24 < HCLK <= 48 => 1WS (2 CPU cycles) */
        latency = LL_FLASH_LATENCY_1;
      }
      else
      {
        /* else HCLKFrequency < 24MHz default LL_FLASH_LATENCY_0 0WS */
        latency = LL_FLASH_LATENCY_0;
      }
    }

    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 */
    timeout = 2u;
    do
    {
      /* Wait for Flash latency to be updated */
      getlatency = LL_FLASH_GetLatency();
      timeout--;
    } while ((getlatency != latency) && (timeout > 0u));

    if(getlatency != latency)
    {
      status = ERROR;
    }
    else
    {
      status = SUCCESS;
    }
  }

  return status;
}

/**
  * @}
  */

/**
  * @}
  */

/** @addtogroup UTILS_LL_Private_Functions
  * @{
  */

/**
  * @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 64000000 Hz is reached                   */
  pllfreq = pllfreq / (((UTILS_PLLInitStruct->PLLR >> RCC_PLLCFGR_PLLR_Pos) + 1U));
  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;
  }

  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));

  /* 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 = LL_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);
  }

  /* Decreasing the number of wait states because of lower CPU frequency */
  if (SystemCoreClock > hclk_frequency)
  {
    /* Set FLASH latency to lowest latency */
    status = LL_SetFlashLatency(hclk_frequency);
  }

  /* Update SystemCoreClock variable */
  if (status == SUCCESS)
  {
    LL_SetSystemCoreClock(hclk_frequency);
  }

  return status;
}

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/