WebSVN – DashDisplay – Diff – /branches/Dashboard_L152_v2/Drivers/STM32L1xx_HAL_Driver/Src/stm32l1xx_hal_wwdg.c

     (+) An MCU reset is also generated if the counter value is refreshed
         before the counter has reached the refresh window value. This
         implies that the counter must be refreshed in a limited window.
     (+) Once enabled the WWDG cannot be disabled except by a system reset.
+    (+) If required by application, an Early Wakeup Interrupt can be triggered
+        in order to be warned before WWDG expiration. The Early Wakeup Interrupt
+        (EWI) can be used if specific safety operations or data logging must
+        be performed before the actual reset is generated. When the downcounter
+        reaches 0x40, interrupt occurs. This mechanism requires WWDG interrupt
+        line to be enabled in NVIC. Once enabled, EWI interrupt cannot be
+        disabled except by a system reset.
     (+) WWDGRST flag in RCC CSR register can be used to inform when a WWDG
         reset occurs.
     (+) The WWDG counter input clock is derived from the APB clock divided
         by a programmable prescaler.
     (+) WWDG clock (Hz) = PCLK1 / (4096 * Prescaler)
         where T[5;0] are the lowest 6 bits of Counter.
     (+) WWDG Counter refresh is allowed between the following limits :
         (++) min time (mS) = 1000 * (Counter - Window) / WWDG clock
         (++) max time (mS) = 1000 * (Counter - 0x40) / WWDG clock
     (+) Typical values:
-        (++) Counter min (T[5;0] = 0x00) @32MHz (PCLK1) with zero prescaler:
+        (++) Counter min (T[5;0] = 0x00) at 32MHz (PCLK1) with zero prescaler:
              max timeout before reset: approximately 41.79µs
-        (++) Counter max (T[5;0] = 0x3F) @32MHz (PCLK1) with prescaler dividing by 8:
+        (++) Counter max (T[5;0] = 0x3F) at 32MHz (PCLK1) with prescaler
+             dividing by 8:
              max timeout before reset: approximately 342.38ms
-  ==============================================================================
                      ##### How to use this driver #####
   ==============================================================================
     *** Common driver usage ***
     ===========================
   [..]
     (+) Enable WWDG APB1 clock using __HAL_RCC_WWDG_CLK_ENABLE().
-    (+) Set the WWDG prescaler, refresh window and counter value
+    (+) Configure the WWDG prescaler, refresh window value, counter value and early
-        using HAL_WWDG_Init() function.
+        interrupt status using HAL_WWDG_Init() function. This will automatically
-    (+) Start the WWDG using HAL_WWDG_Start() function.
+        enable WWDG and start its downcounter. Time reference can be taken from
-        When the WWDG is enabled the counter value should be configured to
+        function exit. Care must be taken to provide a counter value
-        a value greater than 0x40 to prevent generating an immediate reset.
+        greater than 0x40 to prevent generation of immediate reset.
-    (+) Optionally you can enable the Early Wakeup Interrupt (EWI) which is
+    (+) If the Early Wakeup Interrupt (EWI) feature is enabled, an interrupt is
-        generated when the counter reaches 0x40, and then start the WWDG using
+        generated when the counter reaches 0x40. When HAL_WWDG_IRQHandler is
+        triggered by the interrupt service routine, flag will be automatically
-        HAL_WWDG_Start_IT(). At EWI HAL_WWDG_WakeupCallback is executed and user can
+        cleared and HAL_WWDG_WakeupCallback user callback will be executed. User
-        add his own code by customization of callback HAL_WWDG_WakeupCallback.
+        can add his own code by customization of callback HAL_WWDG_WakeupCallback.
-        Once enabled, EWI interrupt cannot be disabled except by a system reset.
     (+) Then the application program must refresh the WWDG counter at regular
         intervals during normal operation to prevent an MCU reset, using
         HAL_WWDG_Refresh() function. This operation must occur only when
         the counter is lower than the refresh window value already programmed.
     *** Callback registration ***
     =============================
   [..]
-    The compilation define  USE_HAL_WWDG_REGISTER_CALLBACKS when set to 1 allows
+    The compilation define USE_HAL_WWDG_REGISTER_CALLBACKS when set to 1 allows
     the user to configure dynamically the driver callbacks. Use Functions
-    @ref HAL_WWDG_RegisterCallback() to register a user callback.
+    HAL_WWDG_RegisterCallback() to register a user callback.
-    (+) Function @ref HAL_WWDG_RegisterCallback() allows to register following
+    (+) Function HAL_WWDG_RegisterCallback() allows to register following
         callbacks:
         (++) EwiCallback : callback for Early WakeUp Interrupt.
         (++) MspInitCallback : WWDG MspInit.
     This function takes as parameters the HAL peripheral handle, the Callback ID
     and a pointer to the user callback function.
-    (+) Use function @ref HAL_WWDG_UnRegisterCallback() to reset a callback to
+    (+) Use function HAL_WWDG_UnRegisterCallback() to reset a callback to
-    the default weak (surcharged) function. @ref HAL_WWDG_UnRegisterCallback()
+    the default weak (surcharged) function. HAL_WWDG_UnRegisterCallback()
     takes as parameters the HAL peripheral handle and the Callback ID.
     This function allows to reset following callbacks:
         (++) EwiCallback : callback for  Early WakeUp Interrupt.
         (++) MspInitCallback : WWDG MspInit.
     [..]
-    When calling @ref HAL_WWDG_Init function, callbacks are reset to the
+    When calling HAL_WWDG_Init function, callbacks are reset to the
     corresponding legacy weak (surcharged) functions:
-    @ref HAL_WWDG_EarlyWakeupCallback() and HAL_WWDG_MspInit() only if they have
+    HAL_WWDG_EarlyWakeupCallback() and HAL_WWDG_MspInit() only if they have
     not been registered before.
     [..]
     When compilation define USE_HAL_WWDG_REGISTER_CALLBACKS is set to 0 or
     not defined, the callback registering feature is not available
     and weak (surcharged) callbacks are used.
     *** WWDG HAL driver macros list ***
     ===================================
     [..]
-      Below the list of most used macros in WWDG HAL driver.
+      Below the list of available macros in WWDG HAL driver.
       (+) __HAL_WWDG_ENABLE: Enable the WWDG peripheral
       (+) __HAL_WWDG_GET_FLAG: Get the selected WWDG's flag status
       (+) __HAL_WWDG_CLEAR_FLAG: Clear the WWDG's pending flags
       (+) __HAL_WWDG_ENABLE_IT: Enable the WWDG early wakeup interrupt
   /* Init the low level hardware */
   hwwdg->MspInitCallback(hwwdg);
 #else
   /* Init the low level hardware */
   HAL_WWDG_MspInit(hwwdg);
-#endif
+#endif /* USE_HAL_WWDG_REGISTER_CALLBACKS */
   /* Set WWDG Counter */
   WRITE_REG(hwwdg->Instance->CR, (WWDG_CR_WDGA | hwwdg->Init.Counter));
   /* Set WWDG Prescaler and Window */
   *           @arg @ref HAL_WWDG_EWI_CB_ID Early WakeUp Interrupt Callback ID
   *           @arg @ref HAL_WWDG_MSPINIT_CB_ID MspInit callback ID
   * @param  pCallback pointer to the Callback function
   * @retval status
   */
-HAL_StatusTypeDef HAL_WWDG_RegisterCallback(WWDG_HandleTypeDef *hwwdg, HAL_WWDG_CallbackIDTypeDef CallbackID, pWWDG_CallbackTypeDef pCallback)
+HAL_StatusTypeDef HAL_WWDG_RegisterCallback(WWDG_HandleTypeDef *hwwdg, HAL_WWDG_CallbackIDTypeDef CallbackID,
+                                            pWWDG_CallbackTypeDef pCallback)
+{
   HAL_StatusTypeDef status = HAL_OK;
   if (pCallback == NULL)
+  {
       break;
+  }
   return status;
+}
-#endif
+#endif /* USE_HAL_WWDG_REGISTER_CALLBACKS */
 /**
   * @}
   */
       /* Early Wakeup registered callback */
       hwwdg->EwiCallback(hwwdg);
 #else
       /* Early Wakeup callback */
       HAL_WWDG_EarlyWakeupCallback(hwwdg);
-#endif
+#endif /* USE_HAL_WWDG_REGISTER_CALLBACKS */
+    }
+  }
+}

Subversion Repositories DashDisplay

(root)/branches/Dashboard_L152_v2/Drivers/STM32L1xx_HAL_Driver/Src/stm32l1xx_hal_wwdg.c – Rev 56 → 61