Revision 0:aae68a400cf2, committed 2018-07-23

Comitter:

JackB

Date:

Mon Jul 23 12:24:16 2018 +0000

Commit message:

WDT

Changed in this revision

diff -r 000000000000 -r aae68a400cf2 WDT.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WDT.cpp	Mon Jul 23 12:24:16 2018 +0000
@@ -0,0 +1,83 @@
+#include "WDT.h"
+
+// Load timeout value in watchdog timer and enable
+void WDT::Configure(float timeout) {
+
+#ifdef LPC    
+    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 = (uint32_t)(timeout * (float)clk);
+    LPC_WDT->WDMOD = 0x3;                   // Enabled and Reset
+#endif   
+#ifdef ST_NUCLEO
+    // see http://embedded-lab.com/blog/?p=9662    
+    #define LsiFreq (45000)
+    
+    uint16_t PrescalerCode;
+    uint16_t Prescaler;
+    uint16_t ReloadValue;
+//    float timeout = 10;
+    float Calculated_timeout;
+
+    if ((timeout * (LsiFreq/4)) < 0x7FF) {
+        PrescalerCode = IWDG_PRESCALER_4;
+        Prescaler = 4;
+    }
+    else if ((timeout * (LsiFreq/8)) < 0xFF0) {
+        PrescalerCode = IWDG_PRESCALER_8;
+        Prescaler = 8;
+    }
+    else if ((timeout * (LsiFreq/16)) < 0xFF0) {
+        PrescalerCode = IWDG_PRESCALER_16;
+        Prescaler = 16;
+    }
+    else if ((timeout * (LsiFreq/32)) < 0xFF0) {
+        PrescalerCode = IWDG_PRESCALER_32;
+        Prescaler = 32;
+    }
+    else if ((timeout * (LsiFreq/64)) < 0xFF0) {
+        PrescalerCode = IWDG_PRESCALER_64;
+        Prescaler = 64;
+    }
+    else if ((timeout * (LsiFreq/128)) < 0xFF0) {
+        PrescalerCode = IWDG_PRESCALER_128;
+        Prescaler = 128;
+    }
+    else {
+        PrescalerCode = IWDG_PRESCALER_256;
+        Prescaler = 256;
+    }
+    
+    // specifies the IWDG Reload value. This parameter must be a number between 0 and 0x0FFF.
+    ReloadValue = (uint32_t)(timeout * (LsiFreq/Prescaler));
+    
+    Calculated_timeout = ((float)(Prescaler * ReloadValue)) / LsiFreq;
+//    printf("WATCHDOG set with prescaler:%d reload value: 0x%X - timeout:%f\n",Prescaler, ReloadValue, Calculated_timeout);
+
+    IWDG->KR = KR_REG_ACCESS_VAL; //Disable write protection of IWDG registers      
+    IWDG->PR = PrescalerCode;      //Set PR value      
+    IWDG->RLR = ReloadValue;      //Set RLR value      
+    IWDG->KR = KR_KEY_RELOAD_VAL;    //Reload IWDG      
+    IWDG->KR = KR_KEY_ENABLE_VAL;    //Start IWDG - See more at: http://embedded-lab.com/blog/?p=9662#sthash.6VNxVSn0.dpuf  
+#endif
+
+    Service();
+}
+
+// "kick" or "feed" the dog - reset the watchdog timer
+// by writing this required bit pattern
+void WDT::Service() {
+#ifdef LPC    
+    LPC_WDT->WDFEED = 0xAA;
+    LPC_WDT->WDFEED = 0x55;
+#endif    
+#ifdef ST_NUCLEO
+    IWDG->KR = KR_KEY_RELOAD_VAL;         //Reload IWDG - See more at: http://embedded-lab.com/blog/?p=9662#sthash.6VNxVSn0.dpuf
+#endif
+}
+
+//    bool WDT::WatchdogCausedReset() {
+//        return wdreset;
+//    }
+ 
+

diff -r 000000000000 -r aae68a400cf2 WDT.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WDT.h	Mon Jul 23 12:24:16 2018 +0000
@@ -0,0 +1,31 @@
+#ifndef __WDT__H_
+#define __WDT__H_
+
+// https://developer.mbed.org/users/nbremond/code/Watchdog/docs/tip/Watchdog_8cpp_source.html
+#include "mbed.h"
+
+#define     KR_KEY_RELOAD_VAL   ((uint16_t)0xAAAA)
+#define     KR_KEY_ENABLE_VAL   ((uint16_t)0xCCCC)
+#define     KR_REG_ACCESS_VAL   ((uint16_t)0x5555)
+
+#define ST_NUCLEO
+
+class WDT {
+public:
+
+//    Watchdog() {
+//        wdreset = false; 
+//    }
+
+// Load timeout value in watchdog timer and enable
+    void Configure(float timeout);
+
+// "kick" or "feed" the dog - reset the watchdog timer
+// by writing this required bit pattern
+    void Service();
+    
+//    bool WatchdogCausedReset();
+ 
+};
+
+#endif