STM32F1单片机检测是否为看门狗

 

/**
  * @brief  Checks whether the specified RCC flag is set or not.
  * @param  RCC_FLAG: specifies the flag to check.
  *   
  *   For @b STM32_Connectivity_line_devices, this parameter can be one of the
  *   following values:
  *     @arg RCC_FLAG_HSIRDY: HSI oscillator clock ready
  *     @arg RCC_FLAG_HSERDY: HSE oscillator clock ready
  *     @arg RCC_FLAG_PLLRDY: PLL clock ready
  *     @arg RCC_FLAG_PLL2RDY: PLL2 clock ready      
  *     @arg RCC_FLAG_PLL3RDY: PLL3 clock ready                           
  *     @arg RCC_FLAG_LSERDY: LSE oscillator clock ready
  *     @arg RCC_FLAG_LSIRDY: LSI oscillator clock ready
  *     @arg RCC_FLAG_PINRST: Pin reset
  *     @arg RCC_FLAG_PORRST: POR/PDR reset
  *     @arg RCC_FLAG_SFTRST: Software reset
  *     @arg RCC_FLAG_IWDGRST: Independent Watchdog reset
  *     @arg RCC_FLAG_WWDGRST: Window Watchdog reset
  *     @arg RCC_FLAG_LPWRRST: Low Power reset
  * 
  *   For @b other_STM32_devices, this parameter can be one of the following values:        
  *     @arg RCC_FLAG_HSIRDY: HSI oscillator clock ready
  *     @arg RCC_FLAG_HSERDY: HSE oscillator clock ready
  *     @arg RCC_FLAG_PLLRDY: PLL clock ready
  *     @arg RCC_FLAG_LSERDY: LSE oscillator clock ready
  *     @arg RCC_FLAG_LSIRDY: LSI oscillator clock ready
  *     @arg RCC_FLAG_PINRST: Pin reset
  *     @arg RCC_FLAG_PORRST: POR/PDR reset
  *     @arg RCC_FLAG_SFTRST: Software reset
  *     @arg RCC_FLAG_IWDGRST: Independent Watchdog reset
  *     @arg RCC_FLAG_WWDGRST: Window Watchdog reset
  *     @arg RCC_FLAG_LPWRRST: Low Power reset
  *   
  * @retval The new state of RCC_FLAG (SET or RESET).
  */
FlagStatus RCC_GetFlagStatus(uint8_t RCC_FLAG)
{
  uint32_t tmp = 0;
  uint32_t statusreg = 0;
  FlagStatus bitstatus = RESET;
  /* Check the parameters */
  assert_param(IS_RCC_FLAG(RCC_FLAG));
 
  /* Get the RCC register index */
  tmp = RCC_FLAG >> 5;
  if (tmp == 1)               /* The flag to check is in CR register */
  {
    statusreg = RCC->CR;
  }
  else if (tmp == 2)          /* The flag to check is in BDCR register */
  {
    statusreg = RCC->BDCR;
  }
  else                       /* The flag to check is in CSR register */
  {
    statusreg = RCC->CSR;
  }
 
  /* Get the flag position */
  tmp = RCC_FLAG & FLAG_Mask;
  if ((statusreg & ((uint32_t)1 << tmp)) != (uint32_t)RESET)
  {
    bitstatus = SET;
  }
  else
  {
    bitstatus = RESET;
  }
 
  /* Return the flag status */
  return bitstatus;
}

这是标准外设库V3.5.0版本带的函数，获取是否为独立看门狗复位按照如下操作：

if(RCC_GetFlagStatus(RCC_FLAG_IWDGRST)!=RESET)
{
    printf("独立看门狗复位\r\n");
}
else
{
    printf("其它复位来源\r\n");
}

注意标志位不会自动清除，需要手动清除，用到以下库函数：

/**
  * @brief  Clears the RCC reset flags.
  * @note   The reset flags are: RCC_FLAG_PINRST, RCC_FLAG_PORRST, RCC_FLAG_SFTRST,
  *   RCC_FLAG_IWDGRST, RCC_FLAG_WWDGRST, RCC_FLAG_LPWRRST
  * @param  None
  * @retval None
  */
void RCC_ClearFlag(void)
{
  /* Set RMVF bit to clear the reset flags */
  RCC->CSR |= CSR_RMVF_Set;
}

程序中检测完标志位后直接调用RCC_ClearFlag();即可清除全部的标志位。