STM32看门狗配置说明

大家好，又见面了，我是你们的朋友全栈君。

系统时钟：

The WWDG clock is prescaled from the APB clock and has a configurable time-window that
can be programmed to detect abnormally late or early application behavior.

/** @defgroup WWDG_Prescaler WWDG Prescaler * @{ */
#define WWDG_PRESCALER_1 0x00000000u /*!< WWDG counter clock = (PCLK1/4096)/1 */
#define WWDG_PRESCALER_2 WWDG_CFR_WDGTB_0 /*!< WWDG counter clock = (PCLK1/4096)/2 */
#define WWDG_PRESCALER_4 WWDG_CFR_WDGTB_1 /*!< WWDG counter clock = (PCLK1/4096)/4 */
#define WWDG_PRESCALER_8 (WWDG_CFR_WDGTB_1 | WWDG_CFR_WDGTB_0) /*!< WWDG counter clock = (PCLK1/4096)/8 */

寄存器配置

  hwwdg.Instance = WWDG;
  hwwdg.Init.Prescaler = WWDG_PRESCALER_1;
  hwwdg.Init.Window = 240;
  hwwdg.Init.Counter = 240;
  hwwdg.Init.EWIMode = WWDG_EWI_DISABLE;
  if (HAL_WWDG_Init(&hwwdg) != HAL_OK)
  { 
   
    Error_Handler();
  }

理论计算时间（1分频）
$$T=\frac{240\ast 4096}{8000000}\ast 1000=122.88ms$$

2分频时间为： 2*122.88 = 245.76ms

喂狗：

/** * @brief Refresh the WWDG. * @param hwwdg pointer to a WWDG_HandleTypeDef structure that contains * the configuration information for the specified WWDG module. * @retval HAL status */
HAL_StatusTypeDef HAL_WWDG_Refresh(WWDG_HandleTypeDef *hwwdg)
{ 
   
  /* Write to WWDG CR the WWDG Counter value to refresh with */
  WRITE_REG(hwwdg->Instance->CR, (hwwdg->Init.Counter));

  /* Return function status */
  return HAL_OK;
}