text: /**
    ********************************************************************************
    * @file    stm8l15x_iwdg.c
    * @author  MCD Application Team
    * @version V1.6.0
    * @date    28-June-2013
    * @brief   This file provides firmware functions to manage the following 
    *          functionalities of the Independent watchdog (IWDG) peripheral:           
    *           - Prescaler and Counter configuration
    *           - IWDG activation
    *
    *  @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 0xFF. When it reaches the end of count value (0x00)
    *          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 Halt and Active Halt mode depending on the configuration of the IWDG_HALT
    *          option byte. (IWDG reset can wake-up from Halt).          
    *            
    *          IWDGF flag in RST_SR register can be used to inform when a IWDG
    *          reset occurs.
    *            
    *          Min-max timeout value @38KHz (LSI): 0.10 ms / ~1.724s
    *          The IWDG timeout may vary due to LSI frequency dispersion. STM8L15x
    *          devices provide the capability to measure the LSI frequency (LSI clock
    *          connected internally to TIM2 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 STM8L15x Reference manual
    *          
    *                            
    *          ===================================================================
    *                                 How to use this driver
    *          ===================================================================
    *          1. Enable write access to IWDG_PR and IWDG_RLR registers using
    *             IWDG_WriteAccessCmd(IWDG_WriteAccess_Enable) function
    *               
    *          2. Configure the IWDG prescaler using IWDG_SetPrescaler() function
    *            
    *          3. 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.
    *            
    *          4. 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)
    *             
    *          5. Then the application program must reload the IWDG counter at regular
    *             intervals during normal operation to prevent an MCU reset, using
    *             IWDG_ReloadCounter() function.      
    *          
    *  @endverbatim
    *    
    ******************************************************************************
    *
    * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
    * You may not use this file except in compliance with the License.
    * You may obtain a copy of the License at:
    *
    *        http://www.st.com/software_license_agreement_liberty_v2
    *
    * Unless required by applicable law or agreed to in writing, software 
    * distributed under the License is distributed on an "AS IS" BASIS, 
    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    * See the License for the specific language governing permissions and
    * limitations under the License.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "stm8l15x_iwdg.h"
  
  /** @addtogroup STM8L15x_StdPeriph_Driver
    * @{
    */
    
  /** @defgroup IWDG 
    * @brief IWDG driver modules
    * @{
    */ 
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* 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(IWDG_WriteAccess_TypeDef IWDG_WriteAccess)
  {
    /* Check the parameters */
    assert_param(IS_IWDG_WRITE_ACCESS_MODE(IWDG_WriteAccess));
    IWDG->KR = IWDG_WriteAccess; /* Write Access */
  }
  
  /**
    * @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(IWDG_Prescaler_TypeDef IWDG_Prescaler)
  {
    /* Check the parameters */
    assert_param(IS_IWDG_PRESCALER_VALUE(IWDG_Prescaler));
    IWDG->PR = IWDG_Prescaler;
  }
  
  /**
    * @brief  Sets IWDG Reload value.
    * @note   Write access should be enabled
    * @param  IWDG_Reload : Reload register value.
    *         This parameter must be a number between 0 and 0xFF.
    * @retval None
    */
  void IWDG_SetReload(uint8_t IWDG_Reload)
  {
    IWDG->RLR = IWDG_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 = IWDG_KEY_REFRESH;
  }
  
  /**
    * @}
    */
  
  /** @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 = IWDG_KEY_ENABLE;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
    
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/