Initialization and de-initialization Functions

Initialization and de-initialization functions. More...

Functions
HAL_StatusTypeDef	HAL_Init (void)
	Configure the Flash prefetch, the Instruction and Data caches, the time base source, NVIC and any required global low level hardware by calling the HAL_MspInit() callback function to be optionally defined in user file stm32l4xx_hal_msp.c. More...
HAL_StatusTypeDef	HAL_DeInit (void)
	De-initialize common part of the HAL and stop the source of time base. More...
void	HAL_MspInit (void)
	Initialize the MSP. More...
void	HAL_MspDeInit (void)
	DeInitialize the MSP. More...
HAL_StatusTypeDef	HAL_InitTick (uint32_t TickPriority)
	This function configures the source of the time base: The time source is configured to have 1ms time base with a dedicated Tick interrupt priority. More...

Detailed Description

Initialization and de-initialization functions.

 ===============================================================================
              ##### Initialization and de-initialization functions #####
 ===============================================================================
    [..]  This section provides functions allowing to:
      (+) Initialize the Flash interface, the NVIC allocation and initial time base
          clock configuration.
      (+) De-initialize common part of the HAL.
      (+) Configure the time base source to have 1ms time base with a dedicated
          Tick interrupt priority.
        (++) SysTick timer is used by default as source of time base, but user
             can eventually implement his proper time base source (a general purpose
             timer for example or other time source), keeping in mind that Time base
             duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and
             handled in milliseconds basis.
        (++) Time base configuration function (HAL_InitTick ()) is called automatically
             at the beginning of the program after reset by HAL_Init() or at any time
             when clock is configured, by HAL_RCC_ClockConfig().
        (++) Source of time base is configured  to generate interrupts at regular
             time intervals. Care must be taken if HAL_Delay() is called from a
             peripheral ISR process, the Tick interrupt line must have higher priority
            (numerically lower) than the peripheral interrupt. Otherwise the caller
            ISR process will be blocked.
       (++) functions affecting time base configurations are declared as __weak
             to make  override possible  in case of other  implementations in user file.

Function Documentation

HAL_DeInit()

HAL_StatusTypeDef HAL_DeInit

(

void

)

De-initialize common part of the HAL and stop the source of time base.

Note

This function is optional.

Return values

HAL

status

Definition at line 196 of file stm32l4xx_hal.c.

{
  /* Reset of all peripherals */
  __HAL_RCC_APB1_FORCE_RESET();
  __HAL_RCC_APB1_RELEASE_RESET();

  __HAL_RCC_APB2_FORCE_RESET();
  __HAL_RCC_APB2_RELEASE_RESET();

  __HAL_RCC_AHB1_FORCE_RESET();
  __HAL_RCC_AHB1_RELEASE_RESET();

  __HAL_RCC_AHB2_FORCE_RESET();
  __HAL_RCC_AHB2_RELEASE_RESET();

  __HAL_RCC_AHB3_FORCE_RESET();
  __HAL_RCC_AHB3_RELEASE_RESET();

  /* De-Init the low level hardware */
  HAL_MspDeInit();

  /* Return function status */
  return HAL_OK;
}

HAL_Init()

HAL_StatusTypeDef HAL_Init

(

void

)

Configure the Flash prefetch, the Instruction and Data caches, the time base source, NVIC and any required global low level hardware by calling the HAL_MspInit() callback function to be optionally defined in user file stm32l4xx_hal_msp.c.

Note

HAL_Init() function is called at the beginning of program after reset and before the clock configuration.

In the default implementation the System Timer (Systick) is used as source of time base. The Systick configuration is based on MSI clock, as MSI is the clock used after a system Reset and the NVIC configuration is set to Priority group 4. Once done, time base tick starts incrementing: the tick variable counter is incremented each 1ms in the SysTick_Handler() interrupt handler.

Return values

HAL

status

Definition at line 152 of file stm32l4xx_hal.c.

{
  HAL_StatusTypeDef  status = HAL_OK;

  /* Configure Flash prefetch, Instruction cache, Data cache */
  /* Default configuration at reset is:                      */
  /* - Prefetch disabled                                     */
  /* - Instruction cache enabled                             */
  /* - Data cache enabled                                    */
#if (INSTRUCTION_CACHE_ENABLE == 0)
   __HAL_FLASH_INSTRUCTION_CACHE_DISABLE();
#endif /* INSTRUCTION_CACHE_ENABLE */

#if (DATA_CACHE_ENABLE == 0)
   __HAL_FLASH_DATA_CACHE_DISABLE();
#endif /* DATA_CACHE_ENABLE */

#if (PREFETCH_ENABLE != 0)
  __HAL_FLASH_PREFETCH_BUFFER_ENABLE();
#endif /* PREFETCH_ENABLE */

  /* Set Interrupt Group Priority */
  HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

  /* Use SysTick as time base source and configure 1ms tick (default clock after Reset is MSI) */
  if (HAL_InitTick(TICK_INT_PRIORITY) != HAL_OK)
  {
    status = HAL_ERROR;
  }
  else
  {
    /* Init the low level hardware */
    HAL_MspInit();
  }

  /* Return function status */
  return status;
}

HAL_InitTick()

__weak HAL_StatusTypeDef HAL_InitTick

(

uint32_t

TickPriority

)

This function configures the source of the time base: The time source is configured to have 1ms time base with a dedicated Tick interrupt priority.

Note

This function is called automatically at the beginning of program after reset by HAL_Init() or at any time when clock is reconfigured by HAL_RCC_ClockConfig().

In the default implementation, SysTick timer is the source of time base. It is used to generate interrupts at regular time intervals. Care must be taken if HAL_Delay() is called from a peripheral ISR process, The SysTick interrupt must have higher priority (numerically lower) than the peripheral interrupt. Otherwise the caller ISR process will be blocked. The function is declared as __weak to be overwritten in case of other implementation in user file.

Parameters

TickPriority

Tick interrupt priority.

Return values

HAL

status

Definition at line 259 of file stm32l4xx_hal.c.

{
  HAL_StatusTypeDef  status = HAL_OK;

  if (uwTickFreq != 0U)
  {
    /*Configure the SysTick to have interrupt in 1ms time basis*/
    if (HAL_SYSTICK_Config(SystemCoreClock / (1000U / uwTickFreq)) == 0U)
    {
      /* Configure the SysTick IRQ priority */
      if (TickPriority < (1UL << __NVIC_PRIO_BITS))
      {
        HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);
        uwTickPrio = TickPriority;
      }
      else
      {
        status = HAL_ERROR;
      }
    }
    else
    {
      status = HAL_ERROR;
    }
  }
  else
  {
    status = HAL_ERROR;
  }

  /* Return function status */
  return status;
}

HAL_MspDeInit()

__weak void HAL_MspDeInit

(

void

)

DeInitialize the MSP.

Return values

None

Definition at line 236 of file stm32l4xx_hal.c.

{
  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_MspDeInit could be implemented in the user file
   */
}

HAL_MspInit()

__weak void HAL_MspInit

(

void

)

Initialize the MSP.

Return values

None

Definition at line 225 of file stm32l4xx_hal.c.

{
  /* NOTE : This function should not be modified, when the callback is needed,
            the HAL_MspInit could be implemented in the user file
   */
}