Diff: targets/cmsis/TARGET_STM/TARGET_DISCO_F303VC/stm32f30x_iwdg.c

Revision:

157:90e3acc479a2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/cmsis/TARGET_STM/TARGET_DISCO_F303VC/stm32f30x_iwdg.c	Fri Apr 11 17:15:06 2014 +0100
@@ -0,0 +1,298 @@
+/**
+  ******************************************************************************
+  * @file    stm32f30x_iwdg.c
+  * @author  MCD Application Team
+  * @version V1.1.0
+  * @date    27-February-2014
+  * @brief   This file provides firmware functions to manage the following 
+  *          functionalities of the Independent watchdog (IWDG) peripheral:           
+  *           + Prescaler and Counter configuration
+  *           + IWDG activation
+  *           + Flag management
+  *
+  @verbatim  
+  
+ ===============================================================================
+                          ##### IWDG features #####
+ ===============================================================================
+    [..] The IWDG can be started by either software or hardware (configurable
+         through option byte).
+    [..] The IWDG is clocked by its own dedicated 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 cannot be disabled
+         (LSI cannot be disabled too), and the counter starts counting down from 
+         the reset value of 0xFFF. When it reaches the end of count value (0x000)
+         a system reset is generated.
+         The IWDG counter should be reloaded at regular intervals to prevent
+         an MCU reset.
+    [..] 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 a IWDG
+         reset occurs.
+    [..] Min-max timeout value @41KHz (LSI): ~0.1ms / ~25.5s
+         The IWDG timeout may vary due to LSI frequency dispersion. STM32F30x
+         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. 
+         For more information, please refer to the STM32F30x Reference manual.
+
+                      ##### How to use this driver #####
+ ===============================================================================
+    [..] This driver allows to use IWDG peripheral with either window option enabled
+         or disabled. To do so follow one of the two procedures below.
+    (#) Window option is enabled:    
+        (++) Start the IWDG using IWDG_Enable() function, when the IWDG is used
+             in software mode (no need to enable the LSI, it will be enabled
+             by hardware).        
+        (++) Enable write access to IWDG_PR and IWDG_RLR registers using
+             IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable) function.
+        (++) Configure the IWDG prescaler using IWDG_SetPrescaler() function.
+        (++) Configure the IWDG counter value using IWDG_SetReload() function.
+             This value will be loaded in the IWDG counter each time the counter
+             is reloaded, then the IWDG will start counting down from this value.
+        (++) Wait for the IWDG registers to be updated using IWDG_GetFlagStatus() function.
+        (++) Configure the IWDG refresh window using IWDG_SetWindowValue() function.
+
+    (#) Window option is disabled:    
+        (++) Enable write access to IWDG_PR and IWDG_RLR registers using
+             IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable) function.
+        (++) Configure the IWDG prescaler using IWDG_SetPrescaler() function.
+        (++) Configure the IWDG counter value using IWDG_SetReload() function.
+             This value will be loaded in the IWDG counter each time the counter
+             is reloaded, then the IWDG will start counting down from this value.
+        (++) Wait for the IWDG registers to be updated using IWDG_GetFlagStatus() function.
+        (++) reload the IWDG counter at regular intervals during normal operation 
+             to prevent an MCU reset, using IWDG_ReloadCounter() function.
+        (++) Start the IWDG using IWDG_Enable() function, when the IWDG is used
+             in software mode (no need to enable the LSI, it will be enabled
+             by hardware).    
+          
+  @endverbatim
+    
+  ******************************************************************************
+  * @attention
+  *
+  * <h2><center>&copy; COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
+  *
+  * Redistribution and use in source and binary forms, with or without modification,
+  * are permitted provided that the following conditions are met:
+  *   1. Redistributions of source code must retain the above copyright notice,
+  *      this list of conditions and the following disclaimer.
+  *   2. Redistributions in binary form must reproduce the above copyright notice,
+  *      this list of conditions and the following disclaimer in the documentation
+  *      and/or other materials provided with the distribution.
+  *   3. Neither the name of STMicroelectronics nor the names of its contributors
+  *      may be used to endorse or promote products derived from this software
+  *      without specific prior written permission.
+  *
+  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+  *
+  ******************************************************************************
+  */
+
+/* Includes ------------------------------------------------------------------*/
+#include "stm32f30x_iwdg.h"
+
+/** @addtogroup STM32F30x_StdPeriph_Driver
+  * @{
+  */
+
+/** @defgroup IWDG 
+  * @brief IWDG driver modules
+  * @{
+  */ 
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* ---------------------- IWDG registers bit mask ----------------------------*/
+/* KR register bit mask */
+#define KR_KEY_RELOAD    ((uint16_t)0xAAAA)
+#define KR_KEY_ENABLE    ((uint16_t)0xCCCC)
+
+/* Private macro -------------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Private functions ---------------------------------------------------------*/
+
+/** @defgroup IWDG_Private_Functions
+  * @{
+  */
+
+/** @defgroup IWDG_Group1 Prescaler and Counter configuration functions
+ *  @brief   Prescaler and Counter configuration functions
+ *
+@verbatim   
+ ===============================================================================
+            ##### Prescaler and Counter configuration functions #####
+ ===============================================================================  
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Enables or disables write access to IWDG_PR and IWDG_RLR registers.
+  * @param  IWDG_WriteAccess: new state of write access to IWDG_PR and IWDG_RLR registers.
+  *   This parameter can be one of the following values:
+  *     @arg IWDG_WriteAccess_Enable: Enable write access to IWDG_PR and IWDG_RLR registers
+  *     @arg IWDG_WriteAccess_Disable: Disable write access to IWDG_PR and IWDG_RLR registers
+  * @retval None
+  */
+void IWDG_WriteAccessCmd(uint16_t IWDG_WriteAccess)
+{
+  /* Check the parameters */
+  assert_param(IS_IWDG_WRITE_ACCESS(IWDG_WriteAccess));
+  IWDG->KR = IWDG_WriteAccess;
+}
+
+/**
+  * @brief  Sets IWDG Prescaler value.
+  * @param  IWDG_Prescaler: specifies the IWDG Prescaler value.
+  *   This parameter can be one of the following values:
+  *     @arg IWDG_Prescaler_4: IWDG prescaler set to 4
+  *     @arg IWDG_Prescaler_8: IWDG prescaler set to 8
+  *     @arg IWDG_Prescaler_16: IWDG prescaler set to 16
+  *     @arg IWDG_Prescaler_32: IWDG prescaler set to 32
+  *     @arg IWDG_Prescaler_64: IWDG prescaler set to 64
+  *     @arg IWDG_Prescaler_128: IWDG prescaler set to 128
+  *     @arg IWDG_Prescaler_256: IWDG prescaler set to 256
+  * @retval None
+  */
+void IWDG_SetPrescaler(uint8_t IWDG_Prescaler)
+{
+  /* Check the parameters */
+  assert_param(IS_IWDG_PRESCALER(IWDG_Prescaler));
+  IWDG->PR = IWDG_Prescaler;
+}
+
+/**
+  * @brief  Sets IWDG Reload value.
+  * @param  Reload: specifies the IWDG Reload value.
+  *   This parameter must be a number between 0 and 0x0FFF.
+  * @retval None
+  */
+void IWDG_SetReload(uint16_t Reload)
+{
+  /* Check the parameters */
+  assert_param(IS_IWDG_RELOAD(Reload));
+  IWDG->RLR = Reload;
+}
+
+/**
+  * @brief  Reloads IWDG counter with value defined in the reload register
+  *   (write access to IWDG_PR and IWDG_RLR registers disabled).
+  * @param  None
+  * @retval None
+  */
+void IWDG_ReloadCounter(void)
+{
+  IWDG->KR = KR_KEY_RELOAD;
+}
+
+
+/**
+  * @brief  Sets the IWDG window value.
+  * @param  WindowValue: specifies the window value to be compared to the downcounter.
+  * @retval None
+  */
+void IWDG_SetWindowValue(uint16_t WindowValue)
+{
+  /* Check the parameters */
+  assert_param(IS_IWDG_WINDOW_VALUE(WindowValue));
+  IWDG->WINR = WindowValue;
+}
+
+/**
+  * @}
+  */
+
+/** @defgroup IWDG_Group2 IWDG activation function
+ *  @brief   IWDG activation function 
+ *
+@verbatim   
+ ===============================================================================
+                    ##### IWDG activation function #####
+ ===============================================================================  
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Enables IWDG (write access to IWDG_PR and IWDG_RLR registers disabled).
+  * @param  None
+  * @retval None
+  */
+void IWDG_Enable(void)
+{
+  IWDG->KR = KR_KEY_ENABLE;
+}
+
+/**
+  * @}
+  */
+
+/** @defgroup IWDG_Group3 Flag management function 
+ *  @brief  Flag management function  
+ *
+@verbatim   
+ ===============================================================================
+                     ##### Flag management function ##### 
+ ===============================================================================  
+
+@endverbatim
+  * @{
+  */
+
+/**
+  * @brief  Checks whether the specified IWDG flag is set or not.
+  * @param  IWDG_FLAG: specifies the flag to check.
+  *   This parameter can be one of the following values:
+  *     @arg IWDG_FLAG_PVU: Prescaler Value Update on going
+  *     @arg IWDG_FLAG_RVU: Reload Value Update on going
+  *     @arg IWDG_FLAG_WVU: Counter Window Value Update on going
+  * @retval The new state of IWDG_FLAG (SET or RESET).
+  */
+FlagStatus IWDG_GetFlagStatus(uint16_t IWDG_FLAG)
+{
+  FlagStatus bitstatus = RESET;
+  /* Check the parameters */
+  assert_param(IS_IWDG_FLAG(IWDG_FLAG));
+  if ((IWDG->SR & IWDG_FLAG) != (uint32_t)RESET)
+  {
+    bitstatus = SET;
+  }
+  else
+  {
+    bitstatus = RESET;
+  }
+  /* Return the flag status */
+  return bitstatus;
+}
+
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+/**
+  * @}
+  */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/