Watchdog.cpp

00001 /// @file Watchdog.cpp provides the interface to the Watchdog module
00002 ///
00003 /// This provides basic Watchdog service for the mbed. You can configure
00004 /// various timeout intervals that meet your system needs. Additionally,
00005 /// it is possible to identify if the Watchdog was the cause of any 
00006 /// system restart.
00007 /// 
00008 /// Adapted from Simon's Watchdog code from http://mbed.org/forum/mbed/topic/508/
00009 ///
00010 /// @note Copyright © 2011 by Smartware Computing, all rights reserved.
00011 ///     This software may be used to derive new software, as long as
00012 ///     this copyright statement remains in the source file.
00013 /// @author David Smart
00014 ///
00015 #include "mbed.h"
00016 #include "Watchdog.h"
00017 
00018 #if defined( TARGET_LPC1768 )
00019 /// Watchdog gets instantiated at the module level
00020 Watchdog::Watchdog() {
00021     wdreset = (LPC_WDT->WDMOD >> 2) & 1;    // capture the cause of the previous reset
00022 }
00023 
00024 /// Load timeout value in watchdog timer and enable
00025 void Watchdog::Configure(float s) {
00026     LPC_WDT->WDCLKSEL = 0x1;                // Set CLK src to PCLK
00027     uint32_t clk = SystemCoreClock / 16;    // WD has a fixed /4 prescaler, PCLK default is /4
00028     LPC_WDT->WDTC = (uint32_t)(s * (float)clk);
00029     LPC_WDT->WDMOD = 0x3;                   // Enabled and Reset
00030     Service();
00031 }
00032 
00033 /// "Service", "kick" or "feed" the dog - reset the watchdog timer
00034 /// by writing this required bit pattern
00035 void Watchdog::Service() {
00036     LPC_WDT->WDFEED = 0xAA;
00037     LPC_WDT->WDFEED = 0x55;
00038 }
00039 
00040 /// get the flag to indicate if the watchdog causes the reset
00041 bool Watchdog::WatchdogCausedReset() {
00042     return wdreset;
00043 }
00044 #elif defined(TARGET_ARCH_GPRS) || defined(TARGET_LPC11U24)
00045 /// Watchdog gets instantiated at the module level
00046 Watchdog::Watchdog() {
00047     wdreset = (LPC_WWDT->MOD >> 2) & 1;    // capture the cause of the previous reset
00048 }
00049 
00050 void Watchdog::Configure(float s) {
00051     LPC_SYSCON->SYSAHBCLKCTRL |= 0x8000;
00052     LPC_SYSCON->PDRUNCFG &= 0xFFBF;
00053     LPC_SYSCON->WDTOSCCTRL = 0x40;
00054     
00055     uint32_t clk = 100000;
00056     LPC_WWDT->TC = s * (float)clk;
00057     
00058     LPC_WWDT->CLKSEL = 0x1;                // Set CLK src to PCLK    
00059     LPC_WWDT->MOD = 0x3;                   // Enabled and Reset
00060     Service();
00061 }
00062 
00063 /// "Service", "kick" or "feed" the dog - reset the watchdog timer
00064 /// by writing this required bit pattern
00065 void Watchdog::Service() {
00066     LPC_WWDT->FEED = 0xAA;
00067     LPC_WWDT->FEED = 0x55;
00068 }
00069 
00070 /// get the flag to indicate if the watchdog causes the reset
00071 bool Watchdog::WatchdogCausedReset() {
00072     return wdreset;
00073 }
00074 #elif defined( TARGET_LPC4088 )
00075 // from Gesotec Gesotec
00076 /// Watchdog gets instantiated at the module level
00077 Watchdog::Watchdog() {
00078     wdreset = (LPC_WDT->MOD >> 2) & 1;    // capture the cause of the previous reset
00079 }
00080  
00081 /// Load timeout value in watchdog timer and enable
00082 void Watchdog::Configure(float s) {
00083     //LPC_WDT->CLKSEL = 0x1;                // Set CLK src to PCLK
00084     uint32_t clk = 500000 / 4;    // WD has a fixed /4 prescaler, and a 500khz oscillator
00085     LPC_WDT->TC = (uint32_t)(s * (float)clk);
00086     LPC_WDT->MOD = 0x3;                   // Enabled and Reset
00087     Service();
00088 }
00089  
00090 /// "Service", "kick" or "feed" the dog - reset the watchdog timer
00091 /// by writing this required bit pattern
00092 void Watchdog::Service() {
00093     LPC_WDT->FEED = 0xAA;
00094     LPC_WDT->FEED = 0x55;
00095 }
00096  
00097 /// get the flag to indicate if the watchdog causes the reset
00098 bool Watchdog::WatchdogCausedReset() {
00099     return wdreset;
00100 }
00101 #elif defined( TARGET_STM )
00102 // Derived from Chau Vo
00103 /// Watchdog gets instantiated at the module level
00104 Watchdog::Watchdog() {
00105     wdreset = (RCC->CSR & (1<<29)) ? true : false;  // read the IWDGRSTF (Independent WD, not the windows WD)
00106 }
00107 
00108 /// Load timeout value in watchdog timer and enable
00109 void Watchdog::Configure(int pr) {
00110     // http://www.st.com/web/en/resource/technical/document/reference_manual/CD00171190.pdf
00111     IWDG->KR  = 0x5555;         // enable write to PR, RLR
00112     IWDG->PR  = pr;             // Init prescaler, page 486 Reference Manual
00113     IWDG->RLR = 0xFFF;          // Init RLR
00114     IWDG->KR  = 0xAAAA;         // Reload the watchdog
00115     IWDG->KR  = 0xCCCC;         // Starts the WD
00116 }
00117 
00118 /// "Service", "kick" or "feed" the dog - reset the watchdog timer
00119 void Watchdog::Service() {
00120     IWDG->KR  = 0xAAAA;
00121 }
00122 
00123 /// get the flag to indicate if the watchdog causes the reset
00124 bool Watchdog::WatchdogCausedReset() {
00125     if (wdreset) {
00126         RCC->CSR |= (1<<24); // clear reset flag
00127     }
00128     return wdreset;
00129 }
00130 #endif