Simple library to manage the WatchDog timer, tested on LPC1768

Files at this revision

API Documentation at this revision

Comitter:
wyunreal
Date:
Sat Jan 03 13:26:51 2015 +0000
Commit message:
Simple library to manage the WatchDog timer

Changed in this revision

WatchDogTimer.cpp Show annotated file Show diff for this revision Revisions of this file
WatchDogTimer.h Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WatchDogTimer.cpp	Sat Jan 03 13:26:51 2015 +0000
@@ -0,0 +1,24 @@
+/**
+ * Apache License
+ * Version 2.0, January 2004
+ * http://www.apache.org/licenses/
+ */
+
+#include "WatchDogTimer.h"
+
+int WatchDogTimer::systemResetReason() {
+    return ((LPC_WDT->WDMOD >> 2) & 1) ? SYSTEM_RESET_WATCH_DOG : SYSTEM_RESET_NORMAL;
+}
+
+WatchDogTimer::WatchDogTimer(float seconds) {
+    LPC_WDT->WDCLKSEL = 0x1;                // Set CLK src to PCLK
+    uint32_t clk = SystemCoreClock / 16;    // WD has a fixed /4 prescaler, PCLK default is /4 
+    LPC_WDT->WDTC = seconds * (float)clk;   // Load WD Timer Constant with value determined by float s
+    LPC_WDT->WDMOD = 0x3;                   // Enabled and Reset        
+    feed();
+}
+
+void WatchDogTimer::feed() {
+    LPC_WDT->WDFEED = 0xAA;
+    LPC_WDT->WDFEED = 0x55;
+}
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WatchDogTimer.h	Sat Jan 03 13:26:51 2015 +0000
@@ -0,0 +1,23 @@
+/**
+ * Apache License
+ * Version 2.0, January 2004
+ * http://www.apache.org/licenses/
+ */
+
+#ifndef WATCH_DOG_TIMER_H
+#define WATCH_DOG_TIMER_H
+
+#include "mbed.h"
+
+class WatchDogTimer {
+public: 
+
+    static const int SYSTEM_RESET_NORMAL = 1;
+    static const int SYSTEM_RESET_WATCH_DOG = 2;
+
+    WatchDogTimer(float seconds);
+    void feed();
+    static int systemResetReason();
+};
+
+#endif
\ No newline at end of file