河北水利局项目

APP/wdg.c

@@ -0,0 +1,53 @@
+#include "wdg.h"
+/*****************************************************************************
+ * Function      : Iwdg_Init
+ * Description   : none
+ * Input         : u8 timeout  为以秒为单位的看门狗超时时间，不得低于1s,看门狗定时器的数据不能超过u16的大小65536
+ * Output        : None
+ * Return        : 
+ * Others        : 
+ * Record
+ * 1.Date        : 20170412
+ *   Author      : barry
+ *   Modification: Created function
+
+*****************************************************************************/
+void Iwdg_Init(u8 timeout)
+{  
+  #define WDG_PRE         256
+  #define WDG_PER_COUNT   (40000/WDG_PRE)
+  #define IWDG_Prescaler  IWDG_Prescaler_256
+
+
+  u8 max_timeout = 0xFFF / WDG_PER_COUNT;
+  
+  u16 reloadCount = 0;
+  
+  timeout = (timeout == 0)? 1:timeout;
+  timeout = (timeout >= max_timeout)? max_timeout: timeout;
+  
+  reloadCount = timeout* WDG_PER_COUNT;
+
+  /* Check if the system has resumed from IWDG reset */
+  if (RCC_GetFlagStatus(RCC_FLAG_IWDGRST) != RESET)
+  {
+    RCC_ClearFlag();
+  }
+
+  /* IWDG timeout equal to 280 ms (the timeout may varies due to LSI frequency
+  dispersion) */
+  /* Enable write access to IWDG_PR and IWDG_RLR registers */
+  IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable);
+
+  /* IWDG counter clock: 40KHz(LSI) / 32 = 1.25 KHz */
+  IWDG_SetPrescaler(IWDG_Prescaler);
+  
+  /* Set counter reload value to 1250, 1s timeout */
+  IWDG_SetReload(reloadCount);
+
+  /* Reload IWDG counter */
+  IWDG_ReloadCounter();
+
+  /* Enable IWDG (the LSI oscillator will be enabled by hardware) */
+  IWDG_Enable();  
+}