Diff: targets/TARGET_STM/TARGET_STM32H7/device/stm32h7xx_hal_iwdg.c

Revision:

189:f392fc9709a3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32H7/device/stm32h7xx_hal_iwdg.c	Wed Feb 20 22:31:08 2019 +0000
@@ -0,0 +1,264 @@
+/**
+  ******************************************************************************
+  * @file    stm32h7xx_hal_iwdg.c
+  * @author  MCD Application Team
+  * @brief   IWDG HAL module driver.
+  *          This file provides firmware functions to manage the following
+  *          functionalities of the Independent Watchdog (IWDG) peripheral:
+  *           + Initialization and Start functions
+  *           + IO operation functions
+  *
+  @verbatim
+  ==============================================================================
+                    ##### IWDG Generic features #####
+  ==============================================================================
+  [..]
+    (+) The IWDG can be started by either software or hardware (configurable
+        through option byte).
+
+    (+) The IWDG is clocked by Low-Speed clock (LSI) and thus stays active even
+        if the main clock fails.
+
+    (+) Once the IWDG is started, the LSI is forced ON and both can not be
+        disabled. The counter starts counting down from the reset value (0xFFF).
+        When it reaches the end of count value (0x000) a reset signal is
+        generated (IWDG reset).
+
+    (+) Whenever the key value 0x0000 AAAA is written in the IWDG_KR register,
+        the IWDG_RLR value is reloaded in the counter and the watchdog reset is
+        prevented.
+
+    (+) The IWDG is implemented in the VDD voltage domain that is still functional
+        in STOP and STANDBY mode (IWDG reset can wake-up from STANDBY).
+        IWDGRST flag in RCC_CSR register can be used to inform when an IWDG
+        reset occurs.
+
+    (+) Debug mode : When the microcontroller enters debug mode (core halted),
+        the IWDG counter either continues to work normally or stops, depending
+        on DBG_IWDG_STOP configuration bit in DBG module, accessible through
+        __HAL_DBGMCU_FREEZE_IWDG() and __HAL_DBGMCU_UNFREEZE_IWDG() macros
+
+    [..] Min-max timeout value @32KHz (LSI): ~125us / ~32.7s
+         The IWDG timeout may vary due to LSI frequency dispersion. STM32H7xx
+         devices provide the capability to measure the LSI frequency (LSI clock
+         connected internally to TIM16 CH1 input capture). The measured value
+         can be used to have an IWDG timeout with an acceptable accuracy.
+
+                     ##### How to use this driver #####
+  ==============================================================================
+  [..]
+    (#) Use IWDG using HAL_IWDG_Init() function to :
+      (+) Enable instance by writing Start keyword in IWDG_KEY register. LSI
+           clock is forced ON and IWDG counter starts downcounting.
+      (+) Enable write access to configuration register: IWDG_PR, IWDG_RLR &
+           IWDG_WINR.
+      (+) Configure the IWDG prescaler and counter reload value. This reload
+           value will be loaded in the IWDG counter each time the watchdog is
+           reloaded, then the IWDG will start counting down from this value.
+      (+) wait for status flags to be reset
+      (+) Depending on window parameter:
+        (++) If Window Init parameter is same as Window register value,
+             nothing more is done but reload counter value in order to exit
+             function withy exact time base.
+        (++) Else modify Window register. This will automatically reload
+             watchdog counter.
+
+    (#) Then the application program must refresh the IWDG counter at regular
+        intervals during normal operation to prevent an MCU reset, using
+        HAL_IWDG_Refresh() function.
+
+     *** IWDG HAL driver macros list ***
+     ====================================
+     [..]
+       Below the list of most used macros in IWDG HAL driver:
+      (+) __HAL_IWDG_START: Enable the IWDG peripheral
+      (+) __HAL_IWDG_RELOAD_COUNTER: Reloads IWDG counter with value defined in
+          the reload register
+
+  @endverbatim
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics.
+  * All rights reserved.</center></h2>
+  *
+  * This software component is licensed by ST under BSD 3-Clause license,
+  * the "License"; You may not use this file except in compliance with the
+  * License. You may obtain a copy of the License at:
+  *                        opensource.org/licenses/BSD-3-Clause
+  *
+  ******************************************************************************
+  */
+
+/* Includes ------------------------------------------------------------------*/
+#include "stm32h7xx_hal.h"
+
+/** @addtogroup STM32H7xx_HAL_Driver
+  * @{
+  */
+
+#ifdef HAL_IWDG_MODULE_ENABLED
+/** @addtogroup IWDG
+  * @brief IWDG HAL module driver.
+  * @{
+  */
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/** @defgroup IWDG_Private_Defines IWDG Private Defines
+  * @{
+  */
+/* Status register need 5 RC LSI divided by prescaler clock to be updated. With
+   higher prescaler (256), and according to LSI variation, we need to wait at
+   least 6 cycles so 48 ms. */
+#define HAL_IWDG_DEFAULT_TIMEOUT            48u
+/**
+  * @}
+  */
+
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Exported functions --------------------------------------------------------*/
+
+/** @addtogroup IWDG_Exported_Functions
+  * @{
+  */
+
+/** @addtogroup IWDG_Exported_Functions_Group1
+ *  @brief    Initialization and Start functions.
+ *
+@verbatim
+ ===============================================================================
+          ##### Initialization and Start functions #####
+ ===============================================================================
+ [..]  This section provides functions allowing to:
+      (+) Initialize the IWDG according to the specified parameters in the
+          IWDG_InitTypeDef of associated handle.
+      (+) Manage Window option.
+      (+) Once initialization is performed in HAL_IWDG_Init function, Watchdog
+          is reloaded in order to exit function with correct time base.
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Initialize the IWDG according to the specified parameters in the
+  *         IWDG_InitTypeDef and start watchdog. Before exiting function,
+  *         watchdog is refreshed in order to have correct time base.
+  * @param  hiwdg  pointer to a IWDG_HandleTypeDef structure that contains
+  *                the configuration information for the specified IWDG module.
+  * @retval HAL status
+  */
+HAL_StatusTypeDef HAL_IWDG_Init(IWDG_HandleTypeDef *hiwdg)
+{
+  uint32_t tickstart;
+
+  /* Check the IWDG handle allocation */
+  if (hiwdg == NULL)
+  {
+    return HAL_ERROR;
+  }
+
+  /* Check the parameters */
+  assert_param(IS_IWDG_ALL_INSTANCE(hiwdg->Instance));
+  assert_param(IS_IWDG_PRESCALER(hiwdg->Init.Prescaler));
+  assert_param(IS_IWDG_RELOAD(hiwdg->Init.Reload));
+  assert_param(IS_IWDG_WINDOW(hiwdg->Init.Window));
+
+  /* Enable IWDG. LSI is turned on automaticaly */
+  __HAL_IWDG_START(hiwdg);
+
+  /* Enable write access to IWDG_PR, IWDG_RLR and IWDG_WINR registers by writing
+  0x5555 in KR */
+  IWDG_ENABLE_WRITE_ACCESS(hiwdg);
+
+  /* Write to IWDG registers the Prescaler & Reload values to work with */
+  hiwdg->Instance->PR = hiwdg->Init.Prescaler;
+  hiwdg->Instance->RLR = hiwdg->Init.Reload;
+
+  /* Check pending flag, if previous update not done, return timeout */
+  tickstart = HAL_GetTick();
+
+  /* Wait for register to be updated */
+  while (hiwdg->Instance->SR != 0x00u)
+  {
+    if ((HAL_GetTick() - tickstart) > HAL_IWDG_DEFAULT_TIMEOUT)
+    {
+      return HAL_TIMEOUT;
+    }
+  }
+
+  /* If window parameter is different than current value, modify window
+  register */
+  if (hiwdg->Instance->WINR != hiwdg->Init.Window)
+  {
+    /* Write to IWDG WINR the IWDG_Window value to compare with. In any case,
+    even if window feature is disabled, Watchdog will be reloaded by writing
+    windows register */
+    hiwdg->Instance->WINR = hiwdg->Init.Window;
+  }
+  else
+  {
+    /* Reload IWDG counter with value defined in the reload register */
+    __HAL_IWDG_RELOAD_COUNTER(hiwdg);
+  }
+
+  /* Return function status */
+  return HAL_OK;
+}
+
+/**
+  * @}
+  */
+
+
+/** @addtogroup IWDG_Exported_Functions_Group2
+ *  @brief   IO operation functions
+ *
+@verbatim
+ ===============================================================================
+                      ##### IO operation functions #####
+ ===============================================================================
+ [..]  This section provides functions allowing to:
+      (+) Refresh the IWDG.
+
+@endverbatim
+  * @{
+  */
+
+
+/**
+  * @brief  Refresh the IWDG.
+  * @param  hiwdg  pointer to a IWDG_HandleTypeDef structure that contains
+  *                the configuration information for the specified IWDG module.
+  * @retval HAL status
+  */
+HAL_StatusTypeDef HAL_IWDG_Refresh(IWDG_HandleTypeDef *hiwdg)
+{
+  /* Reload IWDG counter with value defined in the reload register */
+  __HAL_IWDG_RELOAD_COUNTER(hiwdg);
+
+  /* Return function status */
+  return HAL_OK;
+}
+
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+#endif /* HAL_IWDG_MODULE_ENABLED */
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/