2 ******************************************************************************
3 * @file stm32f7xx_hal_wwdg.c
4 * @author MCD Application Team
7 * @brief WWDG HAL module driver.
8 * This file provides firmware functions to manage the following
9 * functionalities of the Window Watchdog (WWDG) peripheral:
10 * + Initialization and Configuration function
11 * + IO operation functions
13 ==============================================================================
14 ##### WWDG specific features #####
15 ==============================================================================
17 Once enabled the WWDG generates a system reset on expiry of a programmed
18 time period, unless the program refreshes the counter (T[6;0] downcounter)
19 before reaching 0x3F value (i.e. a reset is generated when the counter
20 value rolls over from 0x40 to 0x3F).
22 (+) An MCU reset is also generated if the counter value is refreshed
23 before the counter has reached the refresh window value. This
24 implies that the counter must be refreshed in a limited window.
26 (+) Once enabled the WWDG cannot be disabled except by a system reset.
28 (+) WWDGRST flag in RCC_CSR register informs when a WWDG reset has
29 occurred (check available with __HAL_RCC_GET_FLAG(RCC_FLAG_WWDGRST)).
31 (+) The WWDG downcounter input clock is derived from the APB clock divided
32 by a programmable prescaler.
34 (+) WWDG downcounter clock (Hz) = PCLK1 / (4096 * Prescaler)
36 (+) WWDG timeout (ms) = (1000 * (T[5;0] + 1)) / (WWDG downcounter clock)
37 where T[5;0] are the lowest 6 bits of downcounter.
39 (+) WWDG Counter refresh is allowed between the following limits :
40 (++) min time (ms) = (1000 * (T[5;0] - Window)) / (WWDG downcounter clock)
41 (++) max time (ms) = (1000 * (T[5;0] - 0x40)) / (WWDG downcounter clock)
43 (+) Min-max timeout value @80 MHz(PCLK1): ~51.2 us / ~26.22 ms
45 (+) The Early Wakeup Interrupt (EWI) can be used if specific safety
46 operations or data logging must be performed before the actual reset is
47 generated. When the downcounter reaches the value 0x40, an EWI interrupt
48 is generated and the corresponding interrupt service routine (ISR) can
49 be used to trigger specific actions (such as communications or data
50 logging), before resetting the device.
51 In some applications, the EWI interrupt can be used to manage a software
52 system check and/or system recovery/graceful degradation, without
53 generating a WWDG reset. In this case, the corresponding interrupt
54 service routine (ISR) should reload the WWDG counter to avoid the WWDG
55 reset, then trigger the required actions.
56 Note:When the EWI interrupt cannot be served, e.g. due to a system lock
57 in a higher priority task, the WWDG reset will eventually be generated.
59 (+) Debug mode : When the microcontroller enters debug mode (core halted),
60 the WWDG counter either continues to work normally or stops, depending
61 on DBG_WWDG_STOP configuration bit in DBG module, accessible through
62 __HAL_DBGMCU_FREEZE_WWDG() and __HAL_DBGMCU_UNFREEZE_WWDG() macros
64 ##### How to use this driver #####
65 ==============================================================================
67 (+) Enable WWDG APB1 clock using __HAL_RCC_WWDG_CLK_ENABLE().
69 (+) Set the WWDG prescaler, refresh window, counter value and Early Wakeup
70 Interrupt mode using using HAL_WWDG_Init() function.
71 This enables WWDG peripheral and the downcounter starts downcounting
72 from given counter value.
73 Init function can be called again to modify all watchdog parameters,
74 however if EWI mode has been set once, it can't be clear until next
77 (+) The application program must refresh the WWDG counter at regular
78 intervals during normal operation to prevent an MCU reset using
79 HAL_WWDG_Refresh() function. This operation must occur only when
80 the counter is lower than the window value already programmed.
82 (+) if Early Wakeup Interrupt mode is enable an interrupt is generated when
83 the counter reaches 0x40. User can add his own code in weak function
84 HAL_WWDG_EarlyWakeupCallback().
86 *** WWDG HAL driver macros list ***
87 ==================================
89 Below the list of most used macros in WWDG HAL driver.
91 (+) __HAL_WWDG_GET_IT_SOURCE: Check the selected WWDG's interrupt source.
92 (+) __HAL_WWDG_GET_FLAG: Get the selected WWDG's flag status.
93 (+) __HAL_WWDG_CLEAR_FLAG: Clear the WWDG's pending flags.
96 ******************************************************************************
99 * <h2><center>© COPYRIGHT(c) 2017 STMicroelectronics</center></h2>
101 * Redistribution and use in source and binary forms, with or without modification,
102 * are permitted provided that the following conditions are met:
103 * 1. Redistributions of source code must retain the above copyright notice,
104 * this list of conditions and the following disclaimer.
105 * 2. Redistributions in binary form must reproduce the above copyright notice,
106 * this list of conditions and the following disclaimer in the documentation
107 * and/or other materials provided with the distribution.
108 * 3. Neither the name of STMicroelectronics nor the names of its contributors
109 * may be used to endorse or promote products derived from this software
110 * without specific prior written permission.
112 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
113 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
114 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
115 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
116 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
117 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
118 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
119 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
120 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
121 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
123 ******************************************************************************
126 /* Includes ------------------------------------------------------------------*/
127 #include "stm32f7xx_hal.h"
129 /** @addtogroup STM32F7xx_HAL_Driver
133 #ifdef HAL_WWDG_MODULE_ENABLED
134 /** @defgroup WWDG WWDG
135 * @brief WWDG HAL module driver.
139 /* Private typedef -----------------------------------------------------------*/
140 /* Private define ------------------------------------------------------------*/
141 /* Private macro -------------------------------------------------------------*/
142 /* Private variables ---------------------------------------------------------*/
143 /* Private function prototypes -----------------------------------------------*/
144 /* Exported functions --------------------------------------------------------*/
146 /** @defgroup WWDG_Exported_Functions WWDG Exported Functions
150 /** @defgroup WWDG_Exported_Functions_Group1 Initialization and Configuration functions
151 * @brief Initialization and Configuration functions.
154 ==============================================================================
155 ##### Initialization and Configuration functions #####
156 ==============================================================================
158 This section provides functions allowing to:
159 (+) Initialize and start the WWDG according to the specified parameters
160 in the WWDG_InitTypeDef of associated handle.
161 (+) Initialize the WWDG MSP.
168 * @brief Initialize the WWDG according to the specified.
169 * parameters in the WWDG_InitTypeDef of associated handle.
170 * @param hwwdg pointer to a WWDG_HandleTypeDef structure that contains
171 * the configuration information for the specified WWDG module.
174 HAL_StatusTypeDef
HAL_WWDG_Init(WWDG_HandleTypeDef
*hwwdg
)
176 /* Check the WWDG handle allocation */
182 /* Check the parameters */
183 assert_param(IS_WWDG_ALL_INSTANCE(hwwdg
->Instance
));
184 assert_param(IS_WWDG_PRESCALER(hwwdg
->Init
.Prescaler
));
185 assert_param(IS_WWDG_WINDOW(hwwdg
->Init
.Window
));
186 assert_param(IS_WWDG_COUNTER(hwwdg
->Init
.Counter
));
187 assert_param(IS_WWDG_EWI_MODE(hwwdg
->Init
.EWIMode
));
189 /* Init the low level hardware */
190 HAL_WWDG_MspInit(hwwdg
);
192 /* Set WWDG Counter */
193 WRITE_REG(hwwdg
->Instance
->CR
, (WWDG_CR_WDGA
| hwwdg
->Init
.Counter
));
195 /* Set WWDG Prescaler and Window */
196 WRITE_REG(hwwdg
->Instance
->CFR
, (hwwdg
->Init
.EWIMode
| hwwdg
->Init
.Prescaler
| hwwdg
->Init
.Window
));
198 /* Return function status */
204 * @brief Initialize the WWDG MSP.
205 * @param hwwdg pointer to a WWDG_HandleTypeDef structure that contains
206 * the configuration information for the specified WWDG module.
207 * @note When rewriting this function in user file, mechanism may be added
208 * to avoid multiple initialize when HAL_WWDG_Init function is called
209 * again to change parameters.
212 __weak
void HAL_WWDG_MspInit(WWDG_HandleTypeDef
*hwwdg
)
214 /* Prevent unused argument(s) compilation warning */
217 /* NOTE: This function should not be modified, when the callback is needed,
218 the HAL_WWDG_MspInit could be implemented in the user file
226 /** @defgroup WWDG_Exported_Functions_Group2 IO operation functions
227 * @brief IO operation functions
230 ==============================================================================
231 ##### IO operation functions #####
232 ==============================================================================
234 This section provides functions allowing to:
235 (+) Refresh the WWDG.
236 (+) Handle WWDG interrupt request and associated function callback.
243 * @brief Refresh the WWDG.
244 * @param hwwdg pointer to a WWDG_HandleTypeDef structure that contains
245 * the configuration information for the specified WWDG module.
248 HAL_StatusTypeDef
HAL_WWDG_Refresh(WWDG_HandleTypeDef
*hwwdg
)
250 /* Write to WWDG CR the WWDG Counter value to refresh with */
251 WRITE_REG(hwwdg
->Instance
->CR
, (hwwdg
->Init
.Counter
));
253 /* Return function status */
258 * @brief Handle WWDG interrupt request.
259 * @note The Early Wakeup Interrupt (EWI) can be used if specific safety operations
260 * or data logging must be performed before the actual reset is generated.
261 * The EWI interrupt is enabled by calling HAL_WWDG_Init function with
262 * EWIMode set to WWDG_EWI_ENABLE.
263 * When the downcounter reaches the value 0x40, and EWI interrupt is
264 * generated and the corresponding Interrupt Service Routine (ISR) can
265 * be used to trigger specific actions (such as communications or data
266 * logging), before resetting the device.
267 * @param hwwdg pointer to a WWDG_HandleTypeDef structure that contains
268 * the configuration information for the specified WWDG module.
271 void HAL_WWDG_IRQHandler(WWDG_HandleTypeDef
*hwwdg
)
273 /* Check if Early Wakeup Interrupt is enable */
274 if(__HAL_WWDG_GET_IT_SOURCE(hwwdg
, WWDG_IT_EWI
) != RESET
)
276 /* Check if WWDG Early Wakeup Interrupt occurred */
277 if(__HAL_WWDG_GET_FLAG(hwwdg
, WWDG_FLAG_EWIF
) != RESET
)
279 /* Clear the WWDG Early Wakeup flag */
280 __HAL_WWDG_CLEAR_FLAG(hwwdg
, WWDG_FLAG_EWIF
);
282 /* Early Wakeup callback */
283 HAL_WWDG_EarlyWakeupCallback(hwwdg
);
290 * @brief WWDG Early Wakeup callback.
291 * @param hwwdg pointer to a WWDG_HandleTypeDef structure that contains
292 * the configuration information for the specified WWDG module.
295 __weak
void HAL_WWDG_EarlyWakeupCallback(WWDG_HandleTypeDef
* hwwdg
)
297 /* Prevent unused argument(s) compilation warning */
300 /* NOTE: This function should not be modified, when the callback is needed,
301 the HAL_WWDG_EarlyWakeupCallback could be implemented in the user file
313 #endif /* HAL_WWDG_MODULE_ENABLED */
322 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/