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| 2 | mjames | 1 | /** |
| 2 | ****************************************************************************** |
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| 3 | * @file stm32f0xx_hal_iwdg.c |
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| 4 | * @author MCD Application Team |
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| 5 | * @brief IWDG HAL module driver. |
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| 6 | * This file provides firmware functions to manage the following |
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| 7 | * functionalities of the Independent Watchdog (IWDG) peripheral: |
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| 8 | * + Initialization and Start functions |
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| 9 | * + IO operation functions |
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| 10 | * |
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| 11 | @verbatim |
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| 12 | ============================================================================== |
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| 13 | ##### IWDG Generic features ##### |
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| 14 | ============================================================================== |
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| 15 | [..] |
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| 16 | (+) The IWDG can be started by either software or hardware (configurable |
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| 17 | through option byte). |
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| 18 | |||
| 19 | (+) The IWDG is clocked by Low-Speed clock (LSI) and thus stays active even |
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| 20 | if the main clock fails. |
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| 21 | |||
| 22 | (+) Once the IWDG is started, the LSI is forced ON and both can not be |
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| 23 | disabled. The counter starts counting down from the reset value (0xFFF). |
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| 24 | When it reaches the end of count value (0x000) a reset signal is |
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| 25 | generated (IWDG reset). |
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| 26 | |||
| 27 | (+) Whenever the key value 0x0000 AAAA is written in the IWDG_KR register, |
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| 28 | the IWDG_RLR value is reloaded in the counter and the watchdog reset is |
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| 29 | prevented. |
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| 30 | |||
| 31 | (+) The IWDG is implemented in the VDD voltage domain that is still functional |
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| 32 | in STOP and STANDBY mode (IWDG reset can wake-up from STANDBY). |
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| 33 | IWDGRST flag in RCC_CSR register can be used to inform when an IWDG |
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| 34 | reset occurs. |
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| 35 | |||
| 36 | (+) Debug mode : When the microcontroller enters debug mode (core halted), |
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| 37 | the IWDG counter either continues to work normally or stops, depending |
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| 38 | on DBG_IWDG_STOP configuration bit in DBG module, accessible through |
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| 39 | __HAL_DBGMCU_FREEZE_IWDG() and __HAL_DBGMCU_UNFREEZE_IWDG() macros. |
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| 40 | |||
| 41 | [..] Min-max timeout value @32KHz (LSI): ~125us / ~32.7s |
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| 42 | The IWDG timeout may vary due to LSI frequency dispersion. STM32F0xx |
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| 43 | devices provide the capability to measure the LSI frequency (LSI clock |
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| 44 | connected internally to TIM16 CH1 input capture). The measured value |
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| 45 | can be used to have an IWDG timeout with an acceptable accuracy. |
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| 46 | |||
| 47 | ##### How to use this driver ##### |
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| 48 | ============================================================================== |
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| 49 | [..] |
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| 50 | (#) Use IWDG using HAL_IWDG_Init() function to : |
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| 51 | (++) Enable instance by writing Start keyword in IWDG_KEY register. LSI |
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| 52 | clock is forced ON and IWDG counter starts counting down. |
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| 53 | (++) Enable write access to configuration registers: |
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| 54 | IWDG_PR, IWDG_RLR and IWDG_WINR. |
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| 55 | (++) Configure the IWDG prescaler and counter reload value. This reload |
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| 56 | value will be loaded in the IWDG counter each time the watchdog is |
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| 57 | reloaded, then the IWDG will start counting down from this value. |
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| 58 | (++) Wait for status flags to be reset. |
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| 59 | (++) Depending on window parameter: |
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| 60 | (+++) If Window Init parameter is same as Window register value, |
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| 61 | nothing more is done but reload counter value in order to exit |
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| 62 | function with exact time base. |
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| 63 | (+++) Else modify Window register. This will automatically reload |
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| 64 | watchdog counter. |
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| 65 | |||
| 66 | (#) Then the application program must refresh the IWDG counter at regular |
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| 67 | intervals during normal operation to prevent an MCU reset, using |
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| 68 | HAL_IWDG_Refresh() function. |
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| 69 | |||
| 70 | *** IWDG HAL driver macros list *** |
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| 71 | ==================================== |
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| 72 | [..] |
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| 73 | Below the list of most used macros in IWDG HAL driver: |
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| 74 | (+) __HAL_IWDG_START: Enable the IWDG peripheral |
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| 75 | (+) __HAL_IWDG_RELOAD_COUNTER: Reloads IWDG counter with value defined in |
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| 76 | the reload register |
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| 77 | |||
| 78 | @endverbatim |
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| 79 | ****************************************************************************** |
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| 80 | * @attention |
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| 81 | * |
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| 82 | * <h2><center>© Copyright (c) 2016 STMicroelectronics. |
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| 83 | * All rights reserved.</center></h2> |
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| 84 | * |
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| 85 | * This software component is licensed by ST under BSD 3-Clause license, |
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| 86 | * the "License"; You may not use this file except in compliance with the |
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| 87 | * License. You may obtain a copy of the License at: |
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| 88 | * opensource.org/licenses/BSD-3-Clause |
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| 89 | * |
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| 90 | ****************************************************************************** |
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| 91 | */ |
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| 92 | |||
| 93 | /* Includes ------------------------------------------------------------------*/ |
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| 94 | #include "stm32f0xx_hal.h" |
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| 95 | |||
| 96 | /** @addtogroup STM32F0xx_HAL_Driver |
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| 97 | * @{ |
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| 98 | */ |
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| 99 | |||
| 100 | #ifdef HAL_IWDG_MODULE_ENABLED |
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| 101 | /** @addtogroup IWDG |
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| 102 | * @brief IWDG HAL module driver. |
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| 103 | * @{ |
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| 104 | */ |
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| 105 | |||
| 106 | /* Private typedef -----------------------------------------------------------*/ |
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| 107 | /* Private define ------------------------------------------------------------*/ |
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| 108 | /** @defgroup IWDG_Private_Defines IWDG Private Defines |
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| 109 | * @{ |
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| 110 | */ |
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| 111 | /* Status register need 5 RC LSI divided by prescaler clock to be updated. With |
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| 112 | higher prescaler (256), and according to LSI variation, we need to wait at |
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| 113 | least 6 cycles so 48 ms. */ |
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| 114 | #define HAL_IWDG_DEFAULT_TIMEOUT 48u |
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| 115 | /** |
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| 116 | * @} |
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| 117 | */ |
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| 118 | |||
| 119 | /* Private macro -------------------------------------------------------------*/ |
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| 120 | /* Private variables ---------------------------------------------------------*/ |
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| 121 | /* Private function prototypes -----------------------------------------------*/ |
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| 122 | /* Exported functions --------------------------------------------------------*/ |
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| 123 | |||
| 124 | /** @addtogroup IWDG_Exported_Functions |
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| 125 | * @{ |
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| 126 | */ |
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| 127 | |||
| 128 | /** @addtogroup IWDG_Exported_Functions_Group1 |
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| 129 | * @brief Initialization and Start functions. |
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| 130 | * |
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| 131 | @verbatim |
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| 132 | =============================================================================== |
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| 133 | ##### Initialization and Start functions ##### |
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| 134 | =============================================================================== |
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| 135 | [..] This section provides functions allowing to: |
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| 136 | (+) Initialize the IWDG according to the specified parameters in the |
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| 137 | IWDG_InitTypeDef of associated handle. |
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| 138 | (+) Manage Window option. |
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| 139 | (+) Once initialization is performed in HAL_IWDG_Init function, Watchdog |
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| 140 | is reloaded in order to exit function with correct time base. |
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| 141 | |||
| 142 | @endverbatim |
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| 143 | * @{ |
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| 144 | */ |
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| 145 | |||
| 146 | /** |
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| 147 | * @brief Initialize the IWDG according to the specified parameters in the |
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| 148 | * IWDG_InitTypeDef and start watchdog. Before exiting function, |
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| 149 | * watchdog is refreshed in order to have correct time base. |
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| 150 | * @param hiwdg pointer to a IWDG_HandleTypeDef structure that contains |
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| 151 | * the configuration information for the specified IWDG module. |
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| 152 | * @retval HAL status |
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| 153 | */ |
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| 154 | HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg) |
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| 155 | { |
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| 156 | uint32_t tickstart; |
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| 157 | |||
| 158 | /* Check the IWDG handle allocation */ |
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| 159 | if (hiwdg == NULL) |
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| 160 | { |
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| 161 | return HAL_ERROR; |
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| 162 | } |
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| 163 | |||
| 164 | /* Check the parameters */ |
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| 165 | assert_param(IS_IWDG_ALL_INSTANCE(hiwdg->Instance)); |
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| 166 | assert_param(IS_IWDG_PRESCALER(hiwdg->Init.Prescaler)); |
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| 167 | assert_param(IS_IWDG_RELOAD(hiwdg->Init.Reload)); |
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| 168 | assert_param(IS_IWDG_WINDOW(hiwdg->Init.Window)); |
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| 169 | |||
| 170 | /* Enable IWDG. LSI is turned on automatically */ |
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| 171 | __HAL_IWDG_START(hiwdg); |
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| 172 | |||
| 173 | /* Enable write access to IWDG_PR, IWDG_RLR and IWDG_WINR registers by writing |
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| 174 | 0x5555 in KR */ |
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| 175 | IWDG_ENABLE_WRITE_ACCESS(hiwdg); |
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| 176 | |||
| 177 | /* Write to IWDG registers the Prescaler & Reload values to work with */ |
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| 178 | hiwdg->Instance->PR = hiwdg->Init.Prescaler; |
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| 179 | hiwdg->Instance->RLR = hiwdg->Init.Reload; |
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| 180 | |||
| 181 | /* Check pending flag, if previous update not done, return timeout */ |
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| 182 | tickstart = HAL_GetTick(); |
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| 183 | |||
| 184 | /* Wait for register to be updated */ |
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| 185 | while (hiwdg->Instance->SR != 0x00u) |
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| 186 | { |
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| 187 | if ((HAL_GetTick() - tickstart) > HAL_IWDG_DEFAULT_TIMEOUT) |
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| 188 | { |
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| 189 | return HAL_TIMEOUT; |
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| 190 | } |
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| 191 | } |
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| 192 | |||
| 193 | /* If window parameter is different than current value, modify window |
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| 194 | register */ |
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| 195 | if (hiwdg->Instance->WINR != hiwdg->Init.Window) |
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| 196 | { |
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| 197 | /* Write to IWDG WINR the IWDG_Window value to compare with. In any case, |
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| 198 | even if window feature is disabled, Watchdog will be reloaded by writing |
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| 199 | windows register */ |
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| 200 | hiwdg->Instance->WINR = hiwdg->Init.Window; |
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| 201 | } |
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| 202 | else |
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| 203 | { |
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| 204 | /* Reload IWDG counter with value defined in the reload register */ |
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| 205 | __HAL_IWDG_RELOAD_COUNTER(hiwdg); |
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| 206 | } |
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| 207 | |||
| 208 | /* Return function status */ |
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| 209 | return HAL_OK; |
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| 210 | } |
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| 211 | |||
| 212 | /** |
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| 213 | * @} |
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| 214 | */ |
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| 215 | |||
| 216 | |||
| 217 | /** @addtogroup IWDG_Exported_Functions_Group2 |
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| 218 | * @brief IO operation functions |
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| 219 | * |
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| 220 | @verbatim |
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| 221 | =============================================================================== |
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| 222 | ##### IO operation functions ##### |
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| 223 | =============================================================================== |
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| 224 | [..] This section provides functions allowing to: |
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| 225 | (+) Refresh the IWDG. |
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| 226 | |||
| 227 | @endverbatim |
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| 228 | * @{ |
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| 229 | */ |
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| 230 | |||
| 231 | |||
| 232 | /** |
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| 233 | * @brief Refresh the IWDG. |
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| 234 | * @param hiwdg pointer to a IWDG_HandleTypeDef structure that contains |
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| 235 | * the configuration information for the specified IWDG module. |
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| 236 | * @retval HAL status |
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| 237 | */ |
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| 238 | HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg) |
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| 239 | { |
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| 240 | /* Reload IWDG counter with value defined in the reload register */ |
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| 241 | __HAL_IWDG_RELOAD_COUNTER(hiwdg); |
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| 242 | |||
| 243 | /* Return function status */ |
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| 244 | return HAL_OK; |
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| 245 | } |
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| 246 | |||
| 247 | /** |
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| 248 | * @} |
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| 249 | */ |
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| 250 | |||
| 251 | /** |
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| 252 | * @} |
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| 253 | */ |
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| 254 | |||
| 255 | #endif /* HAL_IWDG_MODULE_ENABLED */ |
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| 256 | /** |
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| 257 | * @} |
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| 258 | */ |
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| 259 | |||
| 260 | /** |
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| 261 | * @} |
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| 262 | */ |
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| 263 | |||
| 264 | /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |