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//*****************************************************************************
//
// watchdog.c - Watchdog timer example.
//
// Copyright (c) 2013-2014 Texas Instruments Incorporated. All rights reserved.
// Software License Agreement
//
// Texas Instruments (TI) is supplying this software for use solely and
// exclusively on TI's microcontroller products. The software is owned by
// TI and/or its suppliers, and is protected under applicable copyright
// laws. You may not combine this software with "viral" open-source
// software in order to form a larger program.
//
// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
// DAMAGES, FOR ANY REASON WHATSOEVER.
//
// This is part of revision 2.1.0.12573 of the EK-TM4C1294XL Firmware Package.
//
//*****************************************************************************
#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/fpu.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/sysctl.h"
#include "driverlib/watchdog.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "drivers/buttons.h"
//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>Watchdog (watchdog)</h1>
//!
//! This example application demonstrates the use of the watchdog as a simple
//! heartbeat for the system. If the watchdog is not periodically fed, it will
//! reset the system. Each time the watchdog is fed, the LED is inverted so
//! that it is easy to see that it is being fed, which occurs once every
//! second. To stop the watchdog being fed and, hence, cause a system reset,
//! press the SW1 button.
//
//*****************************************************************************
//****************************************************************************
//
// System clock rate in Hz.
//
//****************************************************************************
uint32_t g_ui32SysClock;
//*****************************************************************************
//
// Flag to tell the watchdog interrupt handler whether or not to clear the
// interrupt (feed the watchdog).
//
//*****************************************************************************
volatile bool g_bFeedWatchdog = true;
//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif
//*****************************************************************************
//
// The interrupt handler for the watchdog. This feeds the dog (so that the
// processor does not get reset) and winks the LED connected to GPIO B3.
//
//*****************************************************************************
void
WatchdogIntHandler(void)
{
//
// If we have been told to stop feeding the watchdog, return immediately
// without clearing the interrupt. This will cause the system to reset
// next time the watchdog interrupt fires.
//
if(!g_bFeedWatchdog)
{
return;
}
//
// Clear the watchdog interrupt.
//
ROM_WatchdogIntClear(WATCHDOG0_BASE);
//
// Invert the GPIO PN0 value.
//
ROM_GPIOPinWrite(GPIO_PORTN_BASE, GPIO_PIN_0,
(ROM_GPIOPinRead(GPIO_PORTN_BASE, GPIO_PIN_0) ^
GPIO_PIN_0));
}
//*****************************************************************************
//
// This function is called when the SW1 button is pressed.
//
//*****************************************************************************
static int32_t
SW1ButtonPressed(void)
{
//
// Set the flag that tells the interrupt handler not to clear the
// watchdog interrupt.
//
g_bFeedWatchdog = false;
return(0);
}
//*****************************************************************************
//
// This example demonstrates the use of the watchdog timer.
//
//*****************************************************************************
int
main(void)
{
//
// Set the clocking to run directly from the crystal at 120MHz.
//
g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);
//
// Initialize the buttons driver.
//
ButtonsInit();
//
// Enable the peripherals used by this example.
//
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_WDOG0);
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
//
// Enable processor interrupts.
//
ROM_IntMasterEnable();
//
// Set GPIO PN0 as an output. This drives an LED on the board that will
// toggle when a watchdog interrupt is processed.
//
ROM_GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, GPIO_PIN_0);
ROM_GPIOPinWrite(GPIO_PORTN_BASE, GPIO_PIN_0, 0);
//
// Enable the watchdog interrupt.
//
ROM_IntEnable(INT_WATCHDOG);
//
// Set the period of the watchdog timer to 1 second.
//
ROM_WatchdogReloadSet(WATCHDOG0_BASE, g_ui32SysClock);
//
// Enable reset generation from the watchdog timer.
//
ROM_WatchdogResetEnable(WATCHDOG0_BASE);
//
// Enable the watchdog timer.
//
ROM_WatchdogEnable(WATCHDOG0_BASE);
//
// Loop forever while the LED winks as watchdog interrupts are handled.
//
while(1)
{
//
// Poll for the select button pressed
//
uint8_t ui8Buttons = ButtonsPoll(0, 0);
if(ui8Buttons & USR_SW1)
{
SW1ButtonPressed();
while(1)
{
}
}
}
}
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