Revision 2:2873f068f325, committed 2011-06-16

Comitter:

WiredHome

Date:

Thu Jun 16 20:55:38 2011 +0000

Parent:

1:5a1ff72b5915

Child:

3:5959d3d35221

Commit message:

v1.00 initial documented version

Changed in this revision

--- a/Watchdog.cpp	Sun Mar 20 23:24:36 2011 +0000
+++ b/Watchdog.cpp	Thu Jun 16 20:55:38 2011 +0000
@@ -1,4 +1,17 @@
-
+/// @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
+///
 #include "mbed.h"
 #include "Watchdog.h"
 
@@ -6,14 +19,14 @@
 
 /// Watchdog gets instantiated at the module level
 Watchdog::Watchdog() {
-    wdreset = (LPC_WDT->WDMOD >> 2) & 1;
+    wdreset = (LPC_WDT->WDMOD >> 2) & 1;    // capture the cause of the previous reset
 }
 
 /// Load timeout value in watchdog timer and enable
 void Watchdog::Configure(float s) {
     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 = s * (float)clk;
+    LPC_WDT->WDTC = (uint32_t)(s * (float)clk);
     LPC_WDT->WDMOD = 0x3;                   // Enabled and Reset
     Service();
 }

--- a/Watchdog.h	Sun Mar 20 23:24:36 2011 +0000
+++ b/Watchdog.h	Thu Jun 16 20:55:38 2011 +0000
@@ -3,7 +3,8 @@
 /// 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.
+/// system restart, permitting the application code to take appropriate
+/// behavior.
 /// 
 /// Adapted from Simon's Watchdog code from http://mbed.org/forum/mbed/topic/508/
 ///
@@ -12,11 +13,23 @@
 ///     this copyright statement remains in the source file.
 /// @author David Smart
 ///
+/// History
+/// \li v1.00 - 20110616: initial release with some documentation improvements
+///
 #ifndef WATCHDOG_H
 #define WATCHDOG_H
 #include "mbed.h"
 
-/// Watchdog provides the interface to the Watchdog feature
+/// The Watchdog class provides the interface to the Watchdog feature
+///
+/// Embedded programs, by their nature, are usually unattended. If things
+/// go wrong, it is usually important that the system attempts to recover.
+/// Aside from robust software, a hardware watchdog can monitor the
+/// system and initiate a system reset when appropriate.
+///
+/// This Watchdog is patterned after one found elsewhere on the mbed site,
+/// however this one also provides a method for the application software
+/// to determine the cause of the reset - watchdog or otherwise.
 ///
 /// example:
 /// @code
@@ -25,11 +38,14 @@
 /// ...
 /// main() {
 ///    if (wd.WatchdogCausedReset())
-///        pc.printf("Watchdog caused reset. WD being armed for 30s cycle.\r\n");
+///        pc.printf("Watchdog caused reset.\r\n");
 ///      
-///    wd.Configure(30.0);      // sets the timeout interval
+///    wd.Configure(3.0);       // sets the timeout interval
 ///    for (;;) {
 ///         wd.Service();       // kick the dog before the timeout
+///         // do other work
+///    }
+/// }
 /// @endcode
 ///
 class Watchdog {