Initialization and Start functions

Initialization and Start functions. More...

Functions
HAL_StatusTypeDef	HAL_IWDG_Init (IWDG_HandleTypeDef *hiwdg)
	Initialize the IWDG according to the specified parameters in the IWDG_InitTypeDef and start watchdog. Before exiting function, watchdog is refreshed in order to have correct time base. More...

Detailed Description

Initialization and Start functions.

 ===============================================================================
          ##### Initialization and Start functions #####
 ===============================================================================
 [..]  This section provides functions allowing to:
      (+) Initialize the IWDG according to the specified parameters in the
          IWDG_InitTypeDef of associated handle.
      (+) Manage Window option.
      (+) Once initialization is performed in HAL_IWDG_Init function, Watchdog
          is reloaded in order to exit function with correct time base.

Function Documentation

HAL_IWDG_Init()

HAL_StatusTypeDef HAL_IWDG_Init

(

IWDG_HandleTypeDef *

hiwdg

)

Initialize the IWDG according to the specified parameters in the IWDG_InitTypeDef and start watchdog. Before exiting function, watchdog is refreshed in order to have correct time base.

Parameters

hiwdg

pointer to a IWDG_HandleTypeDef structure that contains the configuration information for the specified IWDG module.

Return values

HAL

status

Definition at line 154 of file stm32l4xx_hal_iwdg.c.

{
  uint32_t tickstart;

  /* Check the IWDG handle allocation */
  if (hiwdg == NULL)
  {
    return HAL_ERROR;
  }

  /* Check the parameters */
  assert_param(IS_IWDG_ALL_INSTANCE(hiwdg->Instance));
  assert_param(IS_IWDG_PRESCALER(hiwdg->Init.Prescaler));
  assert_param(IS_IWDG_RELOAD(hiwdg->Init.Reload));
  assert_param(IS_IWDG_WINDOW(hiwdg->Init.Window));

  /* Enable IWDG. LSI is turned on automaticaly */
  __HAL_IWDG_START(hiwdg);

  /* Enable write access to IWDG_PR, IWDG_RLR and IWDG_WINR registers by writing
  0x5555 in KR */
  IWDG_ENABLE_WRITE_ACCESS(hiwdg);

  /* Write to IWDG registers the Prescaler & Reload values to work with */
  hiwdg->Instance->PR = hiwdg->Init.Prescaler;
  hiwdg->Instance->RLR = hiwdg->Init.Reload;

  /* Check pending flag, if previous update not done, return timeout */
  tickstart = HAL_GetTick();

  /* Wait for register to be updated */
  while (hiwdg->Instance->SR != 0x00u)
  {
    if ((HAL_GetTick() - tickstart) > HAL_IWDG_DEFAULT_TIMEOUT)
    {
      return HAL_TIMEOUT;
    }
  }

  /* If window parameter is different than current value, modify window
  register */
  if (hiwdg->Instance->WINR != hiwdg->Init.Window)
  {
    /* Write to IWDG WINR the IWDG_Window value to compare with. In any case,
    even if window feature is disabled, Watchdog will be reloaded by writing
    windows register */
    hiwdg->Instance->WINR = hiwdg->Init.Window;
  }
  else
  {
    /* Reload IWDG counter with value defined in the reload register */
    __HAL_IWDG_RELOAD_COUNTER(hiwdg);
  }

  /* Return function status */
  return HAL_OK;
}