独立看门狗实验

void IWDG_WriteAccessCmd(uint16_t IWDG_WriteAccess);//取消写保护：0x5555使能
void IWDG_SetPrescaler(uint8_t IWDG_Prescaler);//设置预分频系数：写PR
void IWDG_SetReload(uint16_t Reload);//设置重装载值：写RLR
void IWDG_ReloadCounter(void);//喂狗：写0xAAAA到KR
void IWDG_Enable(void);//使能看门狗：写0xCCCC到KR
FlagStatus IWDG_GetFlagStatus(uint16_t IWDG_FLAG);//状态：重装载/预分频 更新

void IWDG_Init(u8 prer,u16 rlr)
{
    IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
    IWDG_SetPrescaler(prer);
    IWDG_SetReload(rlr);
    IWDG_ReloadCounter();
    IWDG_Enable();
}