Thom Bronez / WDT4088s

Version of Watchdog timer for LPC4088 that uses the Singleton design pattern for easy access throughout a program.

Fork of WDT4088 by Kevin Braun

Watchdog.h@1:06813ae93fea, 2016-01-23 (annotated)

Committer:
tbronez
Date:
Sat Jan 23 19:01:31 2016 +0000
Revision:
1:06813ae93fea
Parent:
0:fc62d045ca0c 
Revised using Singleton design pattern to ease use throughout a program.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tbronez 1:06813ae93fea 1 // T. Bronez. rev. 2016-01-23
tbronez 1:06813ae93fea 2 // Based on https://developer.mbed.org/users/loopsva/code/WDT4088/
tbronez 1:06813ae93fea 3 // Put into Singleton design pattern for easy use throughout a program
tbronez 1:06813ae93fea 4
loopsva 0:fc62d045ca0c 5 #ifndef WATCHDOG_4088_H
loopsva 0:fc62d045ca0c 6 #define WATCHDOG_4088_H
loopsva 0:fc62d045ca0c 7
loopsva 0:fc62d045ca0c 8 #include "mbed.h"
loopsva 0:fc62d045ca0c 9
tbronez 1:06813ae93fea 10 /** Routines to enable and feed the Watchdog timer for the LPC4088.
loopsva 0:fc62d045ca0c 11 *
tbronez 1:06813ae93fea 12 * The LPC4088 has a fixed, internal 500KHz oscillator which is divided
tbronez 1:06813ae93fea 13 * by 4 to give an 8uS master clock to the Watchdog countdown timer.
loopsva 0:fc62d045ca0c 14 *
loopsva 0:fc62d045ca0c 15 * User inputs a value from 1 to 134 seconds when initializing the Watchdog
loopsva 0:fc62d045ca0c 16 * timer. The user's input number is multiplied by 125k and then placed into
loopsva 0:fc62d045ca0c 17 * the countdown timer.
loopsva 0:fc62d045ca0c 18 *
tbronez 1:06813ae93fea 19 * The user is responsible for feeding the Watchdog before the timeout
tbronez 1:06813ae93fea 20 * interval expires, otherwise the LPC4088 will automatically reboot.
loopsva 0:fc62d045ca0c 21 *
loopsva 0:fc62d045ca0c 22 * @code
loopsva 0:fc62d045ca0c 23 * #include "mbed.h"
loopsva 0:fc62d045ca0c 24 * #include "Watchdog.h"
loopsva 0:fc62d045ca0c 25 *
loopsva 0:fc62d045ca0c 26 * int main() {
tbronez 1:06813ae93fea 27 * Watchdog* pwd = Watchdog::getInstance();
tbronez 1:06813ae93fea 28 pwd->enable(20); // enable the watchdog with a 20 second timeout
tbronez 1:06813ae93fea 29 * while(1) {
tbronez 1:06813ae93fea 30 * wait_ms(1000); // do some code
tbronez 1:06813ae93fea 31 * pwd->feed(); // feed the watchdog before 20 seconds is up
loopsva 0:fc62d045ca0c 32 * }
loopsva 0:fc62d045ca0c 33 * }
loopsva 0:fc62d045ca0c 34 * @endcode
loopsva 0:fc62d045ca0c 35 *
loopsva 0:fc62d045ca0c 36 */
tbronez 1:06813ae93fea 37
loopsva 0:fc62d045ca0c 38 /* Watchdog controller class
loopsva 0:fc62d045ca0c 39 */
loopsva 0:fc62d045ca0c 40 class Watchdog {
loopsva 0:fc62d045ca0c 41
tbronez 1:06813ae93fea 42 public:
tbronez 1:06813ae93fea 43
tbronez 1:06813ae93fea 44 /* Get the singleton instance, creating it if needed
tbronez 1:06813ae93fea 45 * @returns pointer to watchdog instance
tbronez 1:06813ae93fea 46 */
tbronez 1:06813ae93fea 47 static Watchdog* getInstance();
loopsva 0:fc62d045ca0c 48
tbronez 1:06813ae93fea 49 /** Enable the watchdog
tbronez 1:06813ae93fea 50 * @param int timeout in seconds. Range (1 - 134)
tbronez 1:06813ae93fea 51 */
tbronez 1:06813ae93fea 52 void enable(int WDTseconds);
tbronez 1:06813ae93fea 53
tbronez 1:06813ae93fea 54 /** Keep watchdog quiet by feeding
tbronez 1:06813ae93fea 55 */
tbronez 1:06813ae93fea 56 void feed();
loopsva 0:fc62d045ca0c 57
tbronez 1:06813ae93fea 58 /** Identify reason for reset (watchdog or normal)
tbronez 1:06813ae93fea 59 * @returns true if reset due to watchdog
tbronez 1:06813ae93fea 60 */
tbronez 1:06813ae93fea 61 static bool isWatchdogReset();
tbronez 1:06813ae93fea 62
tbronez 1:06813ae93fea 63 private:
tbronez 1:06813ae93fea 64 // Private constructor
tbronez 1:06813ae93fea 65 Watchdog();
tbronez 1:06813ae93fea 66 // Private copy constructor w/implementation
tbronez 1:06813ae93fea 67 Watchdog(Watchdog const&);
tbronez 1:06813ae93fea 68 // Private assignment operator w/implementation
tbronez 1:06813ae93fea 69 Watchdog& operator=(Watchdog const&);
tbronez 1:06813ae93fea 70 // Global static point to singleton instance
tbronez 1:06813ae93fea 71 static Watchdog* _pInstance;
tbronez 1:06813ae93fea 72
tbronez 1:06813ae93fea 73 int WDTseconds;
loopsva 0:fc62d045ca0c 74 };
loopsva 0:fc62d045ca0c 75
loopsva 0:fc62d045ca0c 76 #endif