STM32L486xx HAL User Manual
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00001 /** 00002 ****************************************************************************** 00003 * @file stm32l4xx_hal_iwdg.c 00004 * @author MCD Application Team 00005 * @brief IWDG HAL module driver. 00006 * This file provides firmware functions to manage the following 00007 * functionalities of the Independent Watchdog (IWDG) peripheral: 00008 * + Initialization and Start functions 00009 * + IO operation functions 00010 * 00011 @verbatim 00012 ============================================================================== 00013 ##### IWDG Generic features ##### 00014 ============================================================================== 00015 [..] 00016 (+) The IWDG can be started by either software or hardware (configurable 00017 through option byte). 00018 00019 (+) The IWDG is clocked by Low-Speed clock (LSI) and thus stays active even 00020 if the main clock fails. 00021 00022 (+) Once the IWDG is started, the LSI is forced ON and both can not be 00023 disabled. The counter starts counting down from the reset value (0xFFF). 00024 When it reaches the end of count value (0x000) a reset signal is 00025 generated (IWDG reset). 00026 00027 (+) Whenever the key value 0x0000 AAAA is written in the IWDG_KR register, 00028 the IWDG_RLR value is reloaded in the counter and the watchdog reset is 00029 prevented. 00030 00031 (+) The IWDG is implemented in the VDD voltage domain that is still functional 00032 in STOP and STANDBY mode (IWDG reset can wake-up from STANDBY). 00033 IWDGRST flag in RCC_CSR register can be used to inform when an IWDG 00034 reset occurs. 00035 00036 (+) Debug mode : When the microcontroller enters debug mode (core halted), 00037 the IWDG counter either continues to work normally or stops, depending 00038 on DBG_IWDG_STOP configuration bit in DBG module, accessible through 00039 __HAL_DBGMCU_FREEZE_IWDG() and __HAL_DBGMCU_UNFREEZE_IWDG() macros 00040 00041 [..] Min-max timeout value @32KHz (LSI): ~125us / ~32.7s 00042 The IWDG timeout may vary due to LSI frequency dispersion. STM32L4xx 00043 devices provide the capability to measure the LSI frequency (LSI clock 00044 connected internally to TIM16 CH1 input capture). The measured value 00045 can be used to have an IWDG timeout with an acceptable accuracy. 00046 00047 ##### How to use this driver ##### 00048 ============================================================================== 00049 [..] 00050 (#) Use IWDG using HAL_IWDG_Init() function to : 00051 (++) Enable instance by writing Start keyword in IWDG_KEY register. LSI 00052 clock is forced ON and IWDG counter starts downcounting. 00053 (++) Enable write access to configuration register: IWDG_PR, IWDG_RLR & 00054 IWDG_WINR. 00055 (++) Configure the IWDG prescaler and counter reload value. This reload 00056 value will be loaded in the IWDG counter each time the watchdog is 00057 reloaded, then the IWDG will start counting down from this value. 00058 (++) Wait for status flags to be reset 00059 (++) Depending on window parameter: 00060 (+++) If Window Init parameter is same as Window register value, 00061 nothing more is done but reload counter value in order to exit 00062 function withy exact time base. 00063 (+++) Else modify Window register. This will automatically reload 00064 watchdog counter. 00065 00066 (#) Then the application program must refresh the IWDG counter at regular 00067 intervals during normal operation to prevent an MCU reset, using 00068 HAL_IWDG_Refresh() function. 00069 00070 *** IWDG HAL driver macros list *** 00071 ==================================== 00072 [..] 00073 Below the list of most used macros in IWDG HAL driver: 00074 (+) __HAL_IWDG_START: Enable the IWDG peripheral 00075 (+) __HAL_IWDG_RELOAD_COUNTER: Reloads IWDG counter with value defined in 00076 the reload register 00077 00078 @endverbatim 00079 ****************************************************************************** 00080 * @attention 00081 * 00082 * <h2><center>© COPYRIGHT(c) 2017 STMicroelectronics</center></h2> 00083 * 00084 * Redistribution and use in source and binary forms, with or without modification, 00085 * are permitted provided that the following conditions are met: 00086 * 1. Redistributions of source code must retain the above copyright notice, 00087 * this list of conditions and the following disclaimer. 00088 * 2. Redistributions in binary form must reproduce the above copyright notice, 00089 * this list of conditions and the following disclaimer in the documentation 00090 * and/or other materials provided with the distribution. 00091 * 3. Neither the name of STMicroelectronics nor the names of its contributors 00092 * may be used to endorse or promote products derived from this software 00093 * without specific prior written permission. 00094 * 00095 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 00096 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00097 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 00098 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE 00099 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00100 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 00101 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00102 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 00103 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 00104 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00105 * 00106 ****************************************************************************** 00107 */ 00108 00109 /* Includes ------------------------------------------------------------------*/ 00110 #include "stm32l4xx_hal.h" 00111 00112 /** @addtogroup STM32L4xx_HAL_Driver 00113 * @{ 00114 */ 00115 00116 #ifdef HAL_IWDG_MODULE_ENABLED 00117 /** @addtogroup IWDG 00118 * @brief IWDG HAL module driver. 00119 * @{ 00120 */ 00121 00122 /* Private typedef -----------------------------------------------------------*/ 00123 /* Private define ------------------------------------------------------------*/ 00124 /** @defgroup IWDG_Private_Defines IWDG Private Defines 00125 * @{ 00126 */ 00127 /* Status register need 5 RC LSI divided by prescaler clock to be updated. With 00128 higher prescaler (256), and according to HSI variation, we need to wait at 00129 least 6 cycles so 48 ms. */ 00130 #define HAL_IWDG_DEFAULT_TIMEOUT 48u 00131 /** 00132 * @} 00133 */ 00134 00135 /* Private macro -------------------------------------------------------------*/ 00136 /* Private variables ---------------------------------------------------------*/ 00137 /* Private function prototypes -----------------------------------------------*/ 00138 /* Exported functions --------------------------------------------------------*/ 00139 00140 /** @addtogroup IWDG_Exported_Functions 00141 * @{ 00142 */ 00143 00144 /** @addtogroup IWDG_Exported_Functions_Group1 00145 * @brief Initialization and Start functions. 00146 * 00147 @verbatim 00148 =============================================================================== 00149 ##### Initialization and Start functions ##### 00150 =============================================================================== 00151 [..] This section provides functions allowing to: 00152 (+) Initialize the IWDG according to the specified parameters in the 00153 IWDG_InitTypeDef of associated handle. 00154 (+) Manage Window option. 00155 (+) Once initialization is performed in HAL_IWDG_Init function, Watchdog 00156 is reloaded in order to exit function with correct time base. 00157 00158 @endverbatim 00159 * @{ 00160 */ 00161 00162 /** 00163 * @brief Initialize the IWDG according to the specified parameters in the 00164 * IWDG_InitTypeDef and start watchdog. Before exiting function, 00165 * watchdog is refreshed in order to have correct time base. 00166 * @param hiwdg pointer to a IWDG_HandleTypeDef structure that contains 00167 * the configuration information for the specified IWDG module. 00168 * @retval HAL status 00169 */ 00170 HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg) 00171 { 00172 uint32_t tickstart; 00173 00174 /* Check the IWDG handle allocation */ 00175 if(hiwdg == NULL) 00176 { 00177 return HAL_ERROR; 00178 } 00179 00180 /* Check the parameters */ 00181 assert_param(IS_IWDG_ALL_INSTANCE(hiwdg->Instance)); 00182 assert_param(IS_IWDG_PRESCALER(hiwdg->Init.Prescaler)); 00183 assert_param(IS_IWDG_RELOAD(hiwdg->Init.Reload)); 00184 assert_param(IS_IWDG_WINDOW(hiwdg->Init.Window)); 00185 00186 /* Enable IWDG. LSI is turned on automaticaly */ 00187 __HAL_IWDG_START(hiwdg); 00188 00189 /* Enable write access to IWDG_PR, IWDG_RLR and IWDG_WINR registers by writing 00190 0x5555 in KR */ 00191 IWDG_ENABLE_WRITE_ACCESS(hiwdg); 00192 00193 /* Write to IWDG registers the Prescaler & Reload values to work with */ 00194 hiwdg->Instance->PR = hiwdg->Init.Prescaler; 00195 hiwdg->Instance->RLR = hiwdg->Init.Reload; 00196 00197 /* Check pending flag, if previous update not done, return timeout */ 00198 tickstart = HAL_GetTick(); 00199 00200 /* Wait for register to be updated */ 00201 while(hiwdg->Instance->SR != RESET) 00202 { 00203 if((HAL_GetTick() - tickstart ) > HAL_IWDG_DEFAULT_TIMEOUT) 00204 { 00205 return HAL_TIMEOUT; 00206 } 00207 } 00208 00209 /* If window parameter is different than current value, modify window 00210 register */ 00211 if(hiwdg->Instance->WINR != hiwdg->Init.Window) 00212 { 00213 /* Write to IWDG WINR the IWDG_Window value to compare with. In any case, 00214 even if window feature is disabled, Watchdog will be reloaded by writing 00215 windows register */ 00216 hiwdg->Instance->WINR = hiwdg->Init.Window; 00217 } 00218 else 00219 { 00220 /* Reload IWDG counter with value defined in the reload register */ 00221 __HAL_IWDG_RELOAD_COUNTER(hiwdg); 00222 } 00223 00224 /* Return function status */ 00225 return HAL_OK; 00226 } 00227 00228 /** 00229 * @} 00230 */ 00231 00232 00233 /** @addtogroup IWDG_Exported_Functions_Group2 00234 * @brief IO operation functions 00235 * 00236 @verbatim 00237 =============================================================================== 00238 ##### IO operation functions ##### 00239 =============================================================================== 00240 [..] This section provides functions allowing to: 00241 (+) Refresh the IWDG. 00242 00243 @endverbatim 00244 * @{ 00245 */ 00246 00247 00248 /** 00249 * @brief Refresh the IWDG. 00250 * @param hiwdg pointer to a IWDG_HandleTypeDef structure that contains 00251 * the configuration information for the specified IWDG module. 00252 * @retval HAL status 00253 */ 00254 HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg) 00255 { 00256 /* Reload IWDG counter with value defined in the reload register */ 00257 __HAL_IWDG_RELOAD_COUNTER(hiwdg); 00258 00259 /* Return function status */ 00260 return HAL_OK; 00261 } 00262 00263 /** 00264 * @} 00265 */ 00266 00267 /** 00268 * @} 00269 */ 00270 00271 #endif /* HAL_IWDG_MODULE_ENABLED */ 00272 /** 00273 * @} 00274 */ 00275 00276 /** 00277 * @} 00278 */ 00279 00280 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/