//選擇 IWDG_Prescaler_128
//64/128 =0.5 khz 2ms周期

#define  IWDG_500MS_REST  (uint8)250#define  IWDG_400MS_REST  (uint8)200#define  IWDG_300MS_REST  (uint8)150#define  IWDG_250MS_REST  (uint8)125#define  IWDG_200MS_REST  (uint8)100#define  IWDG_100MS_REST  (uint8)50#define  IWDG_50MS_REST   (uint8)25#define  IWDG_4MS_REST    (uint8)2IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);//同意操作獨立看門狗IWDG_SetPrescaler(IWDG_Prescaler_128);//看門狗預分頻IWDG_SetReload(IWDG_200MS_REST);//設置看門狗復位時間IWDG_Enable();//啟動獨立看門狗IWDG_ReloadCounter();//看門狗復位 正常使用時不想發生看門狗復位，就運行此指令