STM32的掉电监控PVD

设备在掉电钱及时向flash写入时间，来记录掉电的时间。当下一次上电时读出这个时间。就能知道系统是在什么时候故障掉电的了。

#include "head.h"
#include "PVD.h"

void PVD_Init(void)
{
	EXTI_InitTypeDef EXTI_InitStructure; 
	NVIC_InitTypeDef NVIC_InitStructure;
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); 
	NVIC_InitStructure.NVIC_IRQChannel = PVD_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;  
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; 
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
	
  PWR_PVDLevelConfig(PWR_PVDLevel_2V9); 
  PWR_PVDCmd(ENABLE); 
	EXTI_DeInit();
  EXTI_StructInit(&EXTI_InitStructure);  
  EXTI_InitStructure.EXTI_Line = EXTI_Line16; 
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE; // ʹÄÜÖжÏÏß  
  EXTI_Init(&EXTI_InitStructure); 
	//		EXTI_InitStructure.EXTI_Trigger= EXTI_Trigger_Rising; 
		
}		
extern uint32_t date;		
void  PVD_IRQHandler(void)  
{ 

	if(PWR_GetFlagStatus(PWR_FLAG_PVDO))
	{
		//SET DATE TO FLASH
		FLASH_WriteByte(USER_ADDR , date);
	}
	EXTI_ClearITPendingBit(EXTI_Line16); 
}