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/***************************************************************************//**
* @file
* @brief Watchdog (WDOG) peripheral API
* devices.
* @author Energy Micro AS
* @version 3.0.0
*******************************************************************************
* @section License
* <b>(C) Copyright 2012 Energy Micro AS, http://www.energymicro.com</b>
*******************************************************************************
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
* obligation to support this Software. Energy Micro AS is providing the
* Software "AS IS", with no express or implied warranties of any kind,
* including, but not limited to, any implied warranties of merchantability
* or fitness for any particular purpose or warranties against infringement
* of any proprietary rights of a third party.
*
* Energy Micro AS will not be liable for any consequential, incidental, or
* special damages, or any other relief, or for any claim by any third party,
* arising from your use of this Software.
*
******************************************************************************/
#include "em_wdog.h"
#include "em_bitband.h"
/***************************************************************************//**
* @addtogroup EM_Library
* @{
******************************************************************************/
/***************************************************************************//**
* @addtogroup WDOG
* @brief Watchdog (WDOG) Peripheral API
* @{
******************************************************************************/
/*******************************************************************************
************************** GLOBAL FUNCTIONS *******************************
******************************************************************************/
/***************************************************************************//**
* @brief
* Enable/disable the watchdog timer.
*
* @note
* This function modifies the WDOG CTRL register which requires
* synchronization into the low frequency domain. If this register is modified
* before a previous update to the same register has completed, this function
* will stall until the previous synchronization has completed.
*
* @param[in] enable
* true to enable watchdog, false to disable. Watchdog cannot be disabled if
* watchdog has been locked.
******************************************************************************/
void WDOG_Enable(bool enable)
{
if (!enable)
{
/* Wait for any pending previous write operation to have been completed in */
/* low frequency domain */
while (WDOG->SYNCBUSY & WDOG_SYNCBUSY_CTRL)
;
}
BITBAND_Peripheral(&(WDOG->CTRL), _WDOG_CTRL_EN_SHIFT, (unsigned int)enable);
}
/***************************************************************************//**
* @brief
* Feed the watchdog.
*
* @details
* When the watchdog is activated, it must be fed (ie clearing the counter)
* before it reaches the defined timeout period. Otherwise, the watchdog
* will generate a reset.
******************************************************************************/
void WDOG_Feed(void)
{
/* If a previous clearing is being synchronized to LF domain, then there */
/* is no point in waiting for it to complete before clearing over again. */
/* This avoids stalling the core in the typical use case where some idle loop */
/* keeps clearing the watchdog. */
if (WDOG->SYNCBUSY & WDOG_SYNCBUSY_CMD)
return;
WDOG->CMD = WDOG_CMD_CLEAR;
}
/***************************************************************************//**
* @brief
* Initialize watchdog (assuming the watchdog configuration has not been
* locked).
*
* @note
* This function modifies the WDOG CTRL register which requires
* synchronization into the low frequency domain. If this register is modified
* before a previous update to the same register has completed, this function
* will stall until the previous synchronization has completed.
*
* @param[in] init
* Structure holding watchdog configuration. A default setting
* #WDOG_INIT_DEFAULT is available for init.
******************************************************************************/
void WDOG_Init(const WDOG_Init_TypeDef *init)
{
uint32_t setting;
if (init->enable)
{
setting = WDOG_CTRL_EN;
}
else
{
setting = 0;
}
if (init->debugRun)
{
setting |= WDOG_CTRL_DEBUGRUN;
}
if (init->em2Run)
{
setting |= WDOG_CTRL_EM2RUN;
}
if (init->em3Run)
{
setting |= WDOG_CTRL_EM3RUN;
}
if (init->em4Block)
{
setting |= WDOG_CTRL_EM4BLOCK;
}
if (init->swoscBlock)
{
setting |= WDOG_CTRL_SWOSCBLOCK;
}
setting |= ((uint32_t)(init->clkSel) << _WDOG_CTRL_CLKSEL_SHIFT) |
((uint32_t)(init->perSel) << _WDOG_CTRL_PERSEL_SHIFT);
/* Wait for any pending previous write operation to have been completed in */
/* low frequency domain */
while (WDOG->SYNCBUSY & WDOG_SYNCBUSY_CTRL)
;
WDOG->CTRL = setting;
/* Optional register locking */
if (init->lock)
{
if (init->enable)
{
WDOG_Lock();
}
else
{
BITBAND_Peripheral(&(WDOG->CTRL), _WDOG_CTRL_LOCK_SHIFT, 1);
}
}
}
/***************************************************************************//**
* @brief
* Lock the watchdog configuration.
*
* @details
* This prevents errors from overwriting the watchdog configuration, possibly
* disabling it. Only a reset can unlock the watchdog config, once locked.
*
* If the LFRCO or LFXO clocks are used to clock the watchdog, one should
* consider using the option of inhibiting those clocks to be disabled,
* please see the WDOG_Enable() init structure.
*
* @note
* This function modifies the WDOG CTRL register which requires
* synchronization into the low frequency domain. If this register is modified
* before a previous update to the same register has completed, this function
* will stall until the previous synchronization has completed.
******************************************************************************/
void WDOG_Lock(void)
{
/* Wait for any pending previous write operation to have been completed in */
/* low frequency domain */
while (WDOG->SYNCBUSY & WDOG_SYNCBUSY_CTRL)
;
/* Disable writing to the control register */
BITBAND_Peripheral(&(WDOG->CTRL), _WDOG_CTRL_LOCK_SHIFT, 1);
}
/** @} (end addtogroup WDOG) */
/** @} (end addtogroup EM_Library) */
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