new

Dependencies:   mbed CANMsg

Revision:
0:1e09cd7d66b4
Child:
4:d32258ec411f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/watchdog.cpp	Wed Jun 13 08:52:42 2018 +0000
@@ -0,0 +1,131 @@
+/// @file Watchdog.cpp provides the interface to the Watchdog module
+///
+/// This provides basic Watchdog service for the mbed. You can configure
+/// various timeout intervals that meet your system needs. Additionally,
+/// it is possible to identify if the Watchdog was the cause of any 
+/// system restart.
+/// 
+/// Adapted from Simon's Watchdog code from http://mbed.org/forum/mbed/topic/508/
+///
+/// @note Copyright © 2011 by Smartware Computing, all rights reserved.
+///     This software may be used to derive new software, as long as
+///     this copyright statement remains in the source file.
+/// @author David Smart
+///
+/// @note Copyright © 2015 by NBRemond, all rights reserved.
+///     This software may be used to derive new software, as long as
+///     this copyright statement remains in the source file.
+///
+///     Added support for STM32 Nucleo platforms
+///
+/// @author Bernaérd Remond
+///
+
+//#define LPC
+#define ST_NUCLEO
+
+
+#include "mbed.h"
+#include "watchdog.h"
+
+
+/// Watchdog gets instantiated at the module level
+Watchdog::Watchdog() {
+#ifdef LPC    
+    wdreset = (LPC_WDT->WDMOD >> 2) & 1;    // capture the cause of the previous reset
+#endif
+#ifdef ST_NUCLEO
+    // capture the cause of the previous reset
+    /* Check if the system has resumed from IWDG reset */
+/*
+    if (__HAL_RCC_GET_FLAG(RCC_FLAG_IWDGRST)) {
+        wdreset = true;
+    }
+    else {
+        wdreset = false; 
+    }
+*/        
+        wdreset = false; 
+#endif
+
+}
+
+/// Load timeout value in watchdog timer and enable
+void Watchdog::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 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 = 0x5555; //Disable write protection of IWDG registers      
+    IWDG->PR = PrescalerCode;      //Set PR value      
+    IWDG->RLR = ReloadValue;      //Set RLR value      
+    IWDG->KR = 0xAAAA;    //Reload IWDG      
+    IWDG->KR = 0xCCCC;    //Start IWDG - See more at: http://embedded-lab.com/blog/?p=9662#sthash.6VNxVSn0.dpuf       
+#endif
+ 
+    Service();
+}
+
+/// "Service", "kick" or "feed" the dog - reset the watchdog timer
+/// by writing this required bit pattern
+void Watchdog::Service() {
+#ifdef LPC    
+    LPC_WDT->WDFEED = 0xAA;
+    LPC_WDT->WDFEED = 0x55;
+#endif    
+#ifdef ST_NUCLEO
+    IWDG->KR = 0xAAAA;         //Reload IWDG - See more at: http://embedded-lab.com/blog/?p=9662#sthash.6VNxVSn0.dpuf
+#endif
+}
+
+/// get the flag to indicate if the watchdog causes the reset
+bool Watchdog::WatchdogCausedReset() {
+    return wdreset;
+}
+