int/com/lib/STM32F7xx_HAL_Driver/Src/stm32f7xx_hal_iwdg.c

   1 /**
   2   ******************************************************************************
   3   * @file    stm32f7xx_hal_iwdg.c
   4   * @author  MCD Application Team
   5   * @version V1.1.0
   6   * @date    22-April-2016
   7   * @brief   IWDG HAL module driver.
   8   *          This file provides firmware functions to manage the following
   9   *          functionalities of the Independent Watchdog (IWDG) peripheral:
  10   *           + Initialization and Start functions
  11   *           + IO operation functions
  12   *
  13   @verbatim
  14   ==============================================================================
  15                     ##### IWDG Generic features #####
  16   ==============================================================================
  17   [..]
  18     (+) The IWDG can be started by either software or hardware (configurable
  19         through option byte).
  20
  21     (+) The IWDG is clocked by Low-Speed clock (LSI) and thus stays active even
  22         if the main clock fails.
  23
  24     (+) Once the IWDG is started, the LSI is forced ON and both can not be
  25         disabled. The counter starts counting down from the reset value (0xFFF).
  26         When it reaches the end of count value (0x000) a reset signal is
  27         generated (IWDG reset).
  28
  29     (+) Whenever the key value 0x0000 AAAA is written in the IWDG_KR register,
  30         the IWDG_RLR value is reloaded in the counter and the watchdog reset is
  31         prevented.
  32
  33     (+) The IWDG is implemented in the VDD voltage domain that is still functional
  34         in STOP and STANDBY mode (IWDG reset can wake-up from STANDBY).
  35         IWDGRST flag in RCC_CSR register can be used to inform when an IWDG
  36         reset occurs.
  37
  38     (+) Debug mode : When the microcontroller enters debug mode (core halted),
  39         the IWDG counter either continues to work normally or stops, depending
  40         on DBG_IWDG_STOP configuration bit in DBG module, accessible through
  41         __HAL_DBGMCU_FREEZE_IWDG() and __HAL_DBGMCU_UNFREEZE_IWDG() macros
  42
  43     [..] Min-max timeout value @32KHz (LSI): ~125us / ~32.7s
  44          The IWDG timeout may vary due to LSI frequency dispersion. STM32F7xx
  45          devices provide the capability to measure the LSI frequency (LSI clock
  46          connected internally to TIM16 CH1 input capture). The measured value
  47          can be used to have an IWDG timeout with an acceptable accuracy.
  48
  49                      ##### How to use this driver #####
  50   ==============================================================================
  51   [..]
  52     (#) Use IWDG using HAL_IWDG_Init() function to :
  53       (+) Enable instance by writing Start keyword in IWDG_KEY register. LSI
  54            clock is forced ON and IWDG counter starts downcounting.
  55       (+) Enable write access to configuration register: IWDG_PR, IWDG_RLR &
  56            IWDG_WINR.
  57       (+) Configure the IWDG prescaler and counter reload value. This reload
  58            value will be loaded in the IWDG counter each time the watchdog is
  59            reloaded, then the IWDG will start counting down from this value.
  60       (+) wait for status flags to be reset"
  61       (+) Depending on window parameter:
  62         (++) If Window Init parameter is same as Window register value,
  63              nothing more is done but reload counter value in order to exit
  64              function withy exact time base.
  65         (++) Else modify Window register. This will automatically reload
  66              watchdog counter.
  67
  68     (#) Then the application program must refresh the IWDG counter at regular
  69         intervals during normal operation to prevent an MCU reset, using
  70         HAL_IWDG_Refresh() function.
  71
  72      *** IWDG HAL driver macros list ***
  73      ====================================
  74      [..]
  75        Below the list of most used macros in IWDG HAL driver:
  76       (+) __HAL_IWDG_START: Enable the IWDG peripheral
  77       (+) __HAL_IWDG_RELOAD_COUNTER: Reloads IWDG counter with value defined in
  78           the reload register
  79
  80   @endverbatim
  81   ******************************************************************************
  82   * @attention
  83   *
  84   * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
  85   *
  86   * Redistribution and use in source and binary forms, with or without modification,
  87   * are permitted provided that the following conditions are met:
  88   *   1. Redistributions of source code must retain the above copyright notice,
  89   *      this list of conditions and the following disclaimer.
  90   *   2. Redistributions in binary form must reproduce the above copyright notice,
  91   *      this list of conditions and the following disclaimer in the documentation
  92   *      and/or other materials provided with the distribution.
  93   *   3. Neither the name of STMicroelectronics nor the names of its contributors
  94   *      may be used to endorse or promote products derived from this software
  95   *      without specific prior written permission.
  96   *
  97   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  98   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  99   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 100   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 101   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 102   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 103   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 104   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 105   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 106   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 107   *
 108   ******************************************************************************
 109   */
 110
 111 /* Includes ------------------------------------------------------------------*/
 112 #include "stm32f7xx_hal.h"
 113
 114 /** @addtogroup STM32F7xx_HAL_Driver
 115   * @{
 116   */
 117
 118 #ifdef HAL_IWDG_MODULE_ENABLED
 119 /** @addtogroup IWDG
 120   * @brief IWDG HAL module driver.
 121   * @{
 122   */
 123
 124 /* Private typedef -----------------------------------------------------------*/
 125 /* Private define ------------------------------------------------------------*/
 126 /** @defgroup IWDG_Private_Defines IWDG Private Defines
 127   * @{
 128   */
 129 /* Status register need 5 RC LSI divided by prescaler clock to be updated. With
 130    higher prescaler (256), and according to LSI variation, we need to wait at
 131    least 6 cycles so 48 ms. */
 132 #define HAL_IWDG_DEFAULT_TIMEOUT            48u
 133 /**
 134   * @}
 135   */
 136
 137 /* Private macro -------------------------------------------------------------*/
 138 /* Private variables ---------------------------------------------------------*/
 139 /* Private function prototypes -----------------------------------------------*/
 140 /* Exported functions --------------------------------------------------------*/
 141
 142 /** @addtogroup IWDG_Exported_Functions
 143   * @{
 144   */
 145
 146 /** @addtogroup IWDG_Exported_Functions_Group1
 147  *  @brief    Initialization and Start functions.
 148  *
 149 @verbatim
 150  ===============================================================================
 151           ##### Initialization and Start functions #####
 152  ===============================================================================
 153  [..]  This section provides functions allowing to:
 154       (+) Initialize the IWDG according to the specified parameters in the
 155           IWDG_InitTypeDef of associated handle.
 156       (+) Manage Window option.
 157       (+) Once initialization is performed in HAL_IWDG_Init function, Watchdog
 158           is reloaded in order to exit function with correct time base.
 159
 160 @endverbatim
 161   * @{
 162   */
 163
 164 /**
 165   * @brief  Initialize the IWDG according to the specified parameters in the
 166   *         IWDG_InitTypeDef and start watchdog. Before exiting function,
 167   *         watchdog is refreshed in order to have correct time base.
 168   * @param  hiwdg  pointer to a IWDG_HandleTypeDef structure that contains
 169   *                the configuration information for the specified IWDG module.
 170   * @retval HAL status
 171   */
 172 HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg)
 173 {
 174   uint32_t tickstart;
 175
 176   /* Check the IWDG handle allocation */
 177   if(hiwdg == NULL)
 178   {
 179     return HAL_ERROR;
 180   }
 181
 182   /* Check the parameters */
 183   assert_param(IS_IWDG_ALL_INSTANCE(hiwdg->Instance));
 184   assert_param(IS_IWDG_PRESCALER(hiwdg->Init.Prescaler));
 185   assert_param(IS_IWDG_RELOAD(hiwdg->Init.Reload));
 186   assert_param(IS_IWDG_WINDOW(hiwdg->Init.Window));
 187
 188   /* Enable IWDG. LSI is turned on automaticaly */
 189   __HAL_IWDG_START(hiwdg);
 190
 191   /* Enable write access to IWDG_PR, IWDG_RLR and IWDG_WINR registers by writing
 192   0x5555 in KR */
 193   IWDG_ENABLE_WRITE_ACCESS(hiwdg);
 194
 195   /* Write to IWDG registers the Prescaler & Reload values to work with */
 196   hiwdg->Instance->PR = hiwdg->Init.Prescaler;
 197   hiwdg->Instance->RLR = hiwdg->Init.Reload;
 198
 199   /* Check pending flag, if previous update not done, return timeout */
 200   tickstart = HAL_GetTick();
 201
 202    /* Wait for register to be updated */
 203   while(hiwdg->Instance->SR != RESET)
 204   {
 205     if((HAL_GetTick() - tickstart ) > HAL_IWDG_DEFAULT_TIMEOUT)
 206     {
 207       return HAL_TIMEOUT;
 208     }
 209   }
 210
 211   /* If window parameter is different than current value, modify window
 212   register */
 213   if(hiwdg->Instance->WINR != hiwdg->Init.Window)
 214   {
 215     /* Write to IWDG WINR the IWDG_Window value to compare with. In any case,
 216     even if window feature is disabled, Watchdog will be reloaded by writing
 217     windows register */
 218     hiwdg->Instance->WINR = hiwdg->Init.Window;
 219   }
 220   else
 221   {
 222     /* Reload IWDG counter with value defined in the reload register */
 223     __HAL_IWDG_RELOAD_COUNTER(hiwdg);
 224   }
 225
 226   /* Return function status */
 227   return HAL_OK;
 228 }
 229
 230 /**
 231   * @}
 232   */
 233
 234
 235 /** @addtogroup IWDG_Exported_Functions_Group2
 236  *  @brief   IO operation functions
 237  *
 238 @verbatim
 239  ===============================================================================
 240                       ##### IO operation functions #####
 241  ===============================================================================
 242  [..]  This section provides functions allowing to:
 243       (+) Refresh the IWDG.
 244
 245 @endverbatim
 246   * @{
 247   */
 248
 249
 250 /**
 251   * @brief  Refresh the IWDG.
 252   * @param  hiwdg  pointer to a IWDG_HandleTypeDef structure that contains
 253   *                the configuration information for the specified IWDG module.
 254   * @retval HAL status
 255   */
 256 HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg)
 257 {
 258   /* Reload IWDG counter with value defined in the reload register */
 259   __HAL_IWDG_RELOAD_COUNTER(hiwdg);
 260
 261   /* Return function status */
 262   return HAL_OK;
 263 }
 264
 265 /**
 266   * @}
 267   */
 268
 269 /**
 270   * @}
 271   */
 272
 273 #endif /* HAL_IWDG_MODULE_ENABLED */
 274 /**
 275   * @}
 276   */
 277
 278 /**
 279   * @}
 280   */
 281
 282 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/