text: /*!
      \file    gd32f3x0_fwdgt.c
      \brief   FWDGT driver
  
      \version 2017-06-06, V1.0.0, firmware for GD32F3x0
      \version 2019-06-01, V2.0.0, firmware for GD32F3x0
      \version 2020-09-30, V2.1.0, firmware for GD32F3x0
  */
  
  /*
      Copyright (c) 2020, GigaDevice Semiconductor Inc.
  
      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 the copyright holder 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.
  */
  
  #include "gd32f3x0_fwdgt.h"
  
  /*!
      \brief      enable write access to FWDGT_PSC and FWDGT_RLD
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void fwdgt_write_enable(void)
  {
      FWDGT_CTL = FWDGT_WRITEACCESS_ENABLE;
  }
  
  /*!
      \brief      disable write access to FWDGT_PSC,FWDGT_RLD and FWDGT_WND
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void fwdgt_write_disable(void)
  {
      FWDGT_CTL = FWDGT_WRITEACCESS_DISABLE;
  }
  
  /*!
      \brief      start the free watchdog timer counter
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void fwdgt_enable(void)
  {
      FWDGT_CTL = FWDGT_KEY_ENABLE;
  }
  
  /*!
      \brief      configure the free watchdog timer counter window value
      \param[in]  window_value: specify window value(0x0000 - 0x0FFF)
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus fwdgt_window_value_config(uint16_t window_value)
  {
      uint32_t time_index = FWDGT_WND_TIMEOUT;
      uint32_t flag_status = RESET;
  
      /* enable write access to FWDGT_WND */
      FWDGT_CTL = FWDGT_WRITEACCESS_ENABLE;
  
      /* wait until the WUD flag to be reset */
      do{
          flag_status = FWDGT_STAT & FWDGT_STAT_WUD;
      }while((--time_index > 0U) && (RESET != flag_status));
  
      if (RESET != flag_status){
          return ERROR; 
      }
      
      FWDGT_WND = WND_WND(window_value);
  
      return SUCCESS;
  }
  
  /*!
      \brief      reload the counter of FWDGT
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void fwdgt_counter_reload(void)
  {
      FWDGT_CTL = FWDGT_KEY_RELOAD;
  }
  
  
  /*!
      \brief      configure counter reload value, and prescaler divider value
      \param[in]  reload_value: specify reload value(0x0000 - 0x0FFF)
      \param[in]  prescaler_div: FWDGT prescaler value
                  only one parameter can be selected which is shown as below:
        \arg        FWDGT_PSC_DIV4: FWDGT prescaler set to 4
        \arg        FWDGT_PSC_DIV8: FWDGT prescaler set to 8
        \arg        FWDGT_PSC_DIV16: FWDGT prescaler set to 16
        \arg        FWDGT_PSC_DIV32: FWDGT prescaler set to 32
        \arg        FWDGT_PSC_DIV64: FWDGT prescaler set to 64
        \arg        FWDGT_PSC_DIV128: FWDGT prescaler set to 128
        \arg        FWDGT_PSC_DIV256: FWDGT prescaler set to 256
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus fwdgt_config(uint16_t reload_value, uint8_t prescaler_div)
  {
      uint32_t timeout = FWDGT_PSC_TIMEOUT;
      uint32_t flag_status = RESET;
    
      /* enable write access to FWDGT_PSC,and FWDGT_RLD */
      FWDGT_CTL = FWDGT_WRITEACCESS_ENABLE;
    
      /* wait until the PUD flag to be reset */
      do{
          flag_status = FWDGT_STAT & FWDGT_STAT_PUD;
      }while((--timeout > 0U) && (RESET != flag_status));
      
      if (RESET != flag_status){
          return ERROR;
      }
      
      /* configure FWDGT */
      FWDGT_PSC = (uint32_t)prescaler_div;       
  
      timeout = FWDGT_RLD_TIMEOUT;    
      /* wait until the RUD flag to be reset */
      do{
          flag_status = FWDGT_STAT & FWDGT_STAT_RUD;
      }while((--timeout > 0U) && (RESET != flag_status));
     
      if (RESET != flag_status){
          return ERROR;
      }
      
      FWDGT_RLD = RLD_RLD(reload_value);
      
      /* reload the counter */
      FWDGT_CTL = FWDGT_KEY_RELOAD;
      
      return SUCCESS;
  }
  
  /*!
      \brief      get flag state of FWDGT
      \param[in]  flag: flag to get
                  only one parameter can be selected which is shown as below:
        \arg        FWDGT_FLAG_PUD: a write operation to FWDGT_PSC register is on going
        \arg        FWDGT_FLAG_RUD: a write operation to FWDGT_RLD register is on going
        \arg        FWDGT_FLAG_WUD: a write operation to FWDGT_WND register is on going
      \param[out] none
      \retval     FlagStatus: SET or RESET
  */
  FlagStatus fwdgt_flag_get(uint16_t flag)
  {
    if(FWDGT_STAT & flag){
          return SET;
    }
      return RESET;
  }
  