Bram Kelder / Watchdog

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Fork of Watchdog by David Smart

Watchdog.cpp@7:093e74b9c2c8, 2018-01-09 (annotated)

Committer:
bramkelder
Date:
Tue Jan 09 10:45:36 2018 +0000
Revision:
7:093e74b9c2c8
Parent:
5:2dad2a78ffbd 
removed unneeded boards

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WiredHome 2:2873f068f325 1 /// @file Watchdog.cpp provides the interface to the Watchdog module
WiredHome 2:2873f068f325 2 ///
WiredHome 2:2873f068f325 3 /// This provides basic Watchdog service for the mbed. You can configure
WiredHome 2:2873f068f325 4 /// various timeout intervals that meet your system needs. Additionally,
WiredHome 2:2873f068f325 5 /// it is possible to identify if the Watchdog was the cause of any
WiredHome 2:2873f068f325 6 /// system restart.
WiredHome 2:2873f068f325 7 ///
WiredHome 2:2873f068f325 8 /// Adapted from Simon's Watchdog code from http://mbed.org/forum/mbed/topic/508/
WiredHome 2:2873f068f325 9 ///
WiredHome 2:2873f068f325 10 /// @note Copyright © 2011 by Smartware Computing, all rights reserved.
WiredHome 2:2873f068f325 11 /// This software may be used to derive new software, as long as
WiredHome 2:2873f068f325 12 /// this copyright statement remains in the source file.
WiredHome 2:2873f068f325 13 /// @author David Smart
WiredHome 2:2873f068f325 14 ///
WiredHome 0:7a316f14da9c 15 #include "mbed.h"
WiredHome 0:7a316f14da9c 16 #include "Watchdog.h"
WiredHome 0:7a316f14da9c 17
WiredHome 0:7a316f14da9c 18 /// Watchdog gets instantiated at the module level
WiredHome 0:7a316f14da9c 19 Watchdog::Watchdog() {
WiredHome 2:2873f068f325 20 wdreset = (LPC_WDT->WDMOD >> 2) & 1; // capture the cause of the previous reset
WiredHome 0:7a316f14da9c 21 }
WiredHome 0:7a316f14da9c 22
WiredHome 0:7a316f14da9c 23 /// Load timeout value in watchdog timer and enable
WiredHome 0:7a316f14da9c 24 void Watchdog::Configure(float s) {
WiredHome 0:7a316f14da9c 25 LPC_WDT->WDCLKSEL = 0x1; // Set CLK src to PCLK
WiredHome 0:7a316f14da9c 26 uint32_t clk = SystemCoreClock / 16; // WD has a fixed /4 prescaler, PCLK default is /4
WiredHome 2:2873f068f325 27 LPC_WDT->WDTC = (uint32_t)(s * (float)clk);
WiredHome 0:7a316f14da9c 28 LPC_WDT->WDMOD = 0x3; // Enabled and Reset
WiredHome 0:7a316f14da9c 29 Service();
WiredHome 0:7a316f14da9c 30 }
WiredHome 0:7a316f14da9c 31
WiredHome 0:7a316f14da9c 32 /// "Service", "kick" or "feed" the dog - reset the watchdog timer
WiredHome 0:7a316f14da9c 33 /// by writing this required bit pattern
WiredHome 0:7a316f14da9c 34 void Watchdog::Service() {
WiredHome 0:7a316f14da9c 35 LPC_WDT->WDFEED = 0xAA;
WiredHome 0:7a316f14da9c 36 LPC_WDT->WDFEED = 0x55;
WiredHome 0:7a316f14da9c 37 }
WiredHome 0:7a316f14da9c 38
WiredHome 0:7a316f14da9c 39 /// get the flag to indicate if the watchdog causes the reset
WiredHome 0:7a316f14da9c 40 bool Watchdog::WatchdogCausedReset() {
WiredHome 0:7a316f14da9c 41 return wdreset;
WiredHome 0:7a316f14da9c 42 }