watchdog.c

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/*
 * @brief WWDT example
 *
 * @note
 * Copyright(C) NXP Semiconductors, 2012
 * All rights reserved.
 *
 * @par
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * LPC products.  This software is supplied "AS IS" without any warranties of
 * any kind, and NXP Semiconductors and its licensor disclaim any and
 * all warranties, express or implied, including all implied warranties of
 * merchantability, fitness for a particular purpose and non-infringement of
 * intellectual property rights.  NXP Semiconductors assumes no responsibility
 * or liability for the use of the software, conveys no license or rights under any
 * patent, copyright, mask work right, or any other intellectual property rights in
 * or to any products. NXP Semiconductors reserves the right to make changes
 * in the software without notification. NXP Semiconductors also makes no
 * representation or warranty that such application will be suitable for the
 * specified use without further testing or modification.
 *
 * @par
 * Permission to use, copy, modify, and distribute this software and its
 * documentation is hereby granted, under NXP Semiconductors' and its
 * licensor's relevant copyrights in the software, without fee, provided that it
 * is used in conjunction with NXP Semiconductors microcontrollers.  This
 * copyright, permission, and disclaimer notice must appear in all copies of
 * this code.
 */

#include "board.h"

/*****************************************************************************
 * Private types/enumerations/variables
 ****************************************************************************/

/* Comment this define to let the watchdog timeout. In this case, the board
   will continuously drop via to the WDT warning. */
#define DISABLE_WDT_TIMEOUT

/*****************************************************************************
 * Public types/enumerations/variables
 ****************************************************************************/

/*****************************************************************************
 * Private functions
 ****************************************************************************/

/*****************************************************************************
 * Public functions
 ****************************************************************************/

void WDT_IRQHandler(void)
{
 uint32_t wdtStatus = Chip_WWDT_GetStatus(LPC_WWDT);

#if defined(CHIP_LPC11CXX)
 if (wdtStatus & WWDT_WDMOD_WDTOF) {
  Board_LED_Toggle(0);
  while(Chip_WWDT_GetStatus(LPC_WWDT) & WWDT_WDMOD_WDTOF) {
   Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF);
  }
  Chip_WWDT_Start(LPC_WWDT); /* Needs restart */
 }
#else
 Board_LED_Toggle(0);

 /* The chip will reset before this happens, but if the WDT doesn't
    have WWDT_WDMOD_WDRESET enabled, this will hit once */
 if (wdtStatus & WWDT_WDMOD_WDTOF) {
  /* A watchdog feed didn't occur prior to window timeout */
  Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF);
  Chip_WWDT_Start(LPC_WWDT); /* Needs restart */
 }

 /* Handle warning interrupt */
 if (wdtStatus & WWDT_WDMOD_WDINT) {
  /* A watchdog feed didn't occur prior to warning timeout */
  Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDINT);
  Chip_WWDT_Feed(LPC_WWDT);
 }
#endif
}

void SysTick_Handler(void)
{
#if !defined(DISABLE_WDT_TIMEOUT)
 Chip_WWDT_Feed(LPC_WWDT);
#endif
}

int main(void)
{
 uint32_t wdtFreq;

 /* Board Setup */
 Board_Init();

 /* Initialize WWDT (also enables WWDT clock) */
 Chip_WWDT_Init(LPC_WWDT);

 /* Prior to initializing the watchdog driver, the clocking for the
    watchdog must be enabled. This example uses the watchdog oscillator
    set at a 50KHz (1Mhz / 20) clock rate. */
 Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_WDTOSC_PD);
 Chip_Clock_SetWDTOSC(WDTLFO_OSC_1_05, 20);

 /* The WDT divides the input frequency into it by 4 */
 wdtFreq = Chip_Clock_GetWDTOSCRate() / 4;

 /* LPC1102/4, LPC11XXLV, and LPC11CXX devices select the watchdog
    clock source from the SYSCLK block, while LPC11AXX, LPC11EXX, and
    LPC11UXX devices select the clock as part of the watchdog block. */
 /* Select watchdog oscillator for WDT clock source */
#if defined(CHIP_LPC110X) || defined(CHIP_LPC11XXLV) || defined(CHIP_LPC11CXX) || defined(CHIP_LPC11EXX)
 Chip_Clock_SetWDTClockSource(SYSCTL_WDTCLKSRC_WDTOSC, 1);
#else
 Chip_WWDT_SelClockSource(LPC_WWDT, WWDT_CLKSRC_WATCHDOG_WDOSC);
#endif

 Board_LED_Set(0, false);

 /* Set watchdog feed time constant to approximately 2s
    Set watchdog warning time to 512 ticks after feed time constant
    Set watchdog window time to 3s */
 Chip_WWDT_SetTimeOut(LPC_WWDT, wdtFreq * 2);
#if !defined(CHIP_LPC11CXX)
 Chip_WWDT_SetWarning(LPC_WWDT, 512);
 Chip_WWDT_SetWindow(LPC_WWDT, wdtFreq * 3);
#endif

#if !defined(CHIP_LPC11CXX)
 /* Configure WWDT to reset on timeout */
 Chip_WWDT_SetOption(LPC_WWDT, WWDT_WDMOD_WDRESET);
#endif

 /* Setup Systick to feed the watchdog timer. This needs to be done
  * at a rate faster than the WDT warning. */
 SysTick_Config(Chip_Clock_GetSystemClockRate() / 50);

 /* Clear watchdog warning and timeout interrupts */
#if !defined(CHIP_LPC11CXX) 
 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF | WWDT_WDMOD_WDINT);
#else
 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF);
#endif 

 /* Clear and enable watchdog interrupt */
 NVIC_ClearPendingIRQ(WDT_IRQn);
 NVIC_EnableIRQ(WDT_IRQn);

 /* Start watchdog */
 Chip_WWDT_Start(LPC_WWDT);

 /* Idle while waiting */
 while (1) {
  __WFI();
 }
}