text: /*!
      \file    gd32f4xx_rtc.c
      \brief   RTC driver
  
      \version 2016-08-15, V1.0.0, firmware for GD32F4xx
      \version 2018-12-12, V2.0.0, firmware for GD32F4xx
      \version 2020-09-30, V2.1.0, firmware for GD32F4xx
  */
  
  /*
      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 "gd32f4xx_rtc.h"
  
  /* RTC timeout value */
  #define RTC_WTWF_TIMEOUT                   ((uint32_t)0x00004000U)                    /*!< wakeup timer can be write flag timeout */
  #define RTC_INITM_TIMEOUT                  ((uint32_t)0x00004000U)                    /*!< initialization state flag timeout */
  #define RTC_RSYNF_TIMEOUT                  ((uint32_t)0x00008000U)                    /*!< register synchronization flag timeout */
  #define RTC_HRFC_TIMEOUT                   ((uint32_t)0x20000000U)                    /*!< recalibration pending flag timeout */
  #define RTC_SHIFTCTL_TIMEOUT               ((uint32_t)0x00001000U)                    /*!< shift function operation pending flag timeout */
  #define RTC_ALRMXWF_TIMEOUT                ((uint32_t)0x00008000U)                    /*!< alarm configuration can be write flag timeout */
  
  
  /*!
      \brief      reset most of the RTC registers
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_deinit(void)
  {
      ErrStatus error_status = ERROR;
      volatile uint32_t time_index = RTC_WTWF_TIMEOUT;
      uint32_t flag_status = RESET;
      /* RTC_TAMP register is not under write protection */
      RTC_TAMP = RTC_REGISTER_RESET;
  
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      /* enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){
          /* reset RTC_CTL register, but RTC_CTL[2��0] */
          RTC_CTL &= (RTC_REGISTER_RESET | RTC_CTL_WTCS);
          /* before reset RTC_TIME and RTC_DATE, BPSHAD bit in RTC_CTL should be reset as the condition.
             in order to read calendar from shadow register, not the real registers being reset */
          RTC_TIME = RTC_REGISTER_RESET;
          RTC_DATE = RTC_DATE_RESET;
  
          RTC_PSC = RTC_PSC_RESET;
          /* only when RTC_CTL_WTEN=0 and RTC_STAT_WTWF=1 can write RTC_CTL[2��0] */
          /* wait until the WTWF flag to be set */
          do{
             flag_status = RTC_STAT & RTC_STAT_WTWF;
          }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
  
          if ((uint32_t)RESET == flag_status){
              error_status = ERROR;
          }else{
              RTC_CTL &= RTC_REGISTER_RESET;
              RTC_WUT = RTC_WUT_RESET;
              RTC_COSC = RTC_REGISTER_RESET;
              /* to write RTC_ALRMxSS register, ALRMxEN bit in RTC_CTL register should be reset as the condition */
              RTC_ALRM0TD = RTC_REGISTER_RESET;        
              RTC_ALRM1TD = RTC_REGISTER_RESET;
              RTC_ALRM0SS = RTC_REGISTER_RESET;
              RTC_ALRM1SS = RTC_REGISTER_RESET;
              /* reset RTC_STAT register, also exit init mode.
                 at the same time, RTC_STAT_SOPF bit is reset, as the condition to reset RTC_SHIFTCTL register later */
              RTC_STAT = RTC_STAT_RESET;
              /* reset RTC_SHIFTCTL and RTC_HRFC register, this can be done without the init mode */
              RTC_SHIFTCTL   = RTC_REGISTER_RESET;       
              RTC_HRFC       = RTC_REGISTER_RESET;
              error_status = rtc_register_sync_wait(); 
          }
      }
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      initialize RTC registers
      \param[in]  rtc_initpara_struct: pointer to a rtc_parameter_struct structure which contains 
                  parameters for initialization of the rtc peripheral
                  members of the structure and the member values are shown as below:
                    year: 0x0 - 0x99(BCD format)
                    month: RTC_JAN, RTC_FEB, RTC_MAR, RTC_APR, RTC_MAY, RTC_JUN,
                               RTC_JUL, RTC_AUG, RTC_SEP, RTC_OCT, RTC_NOV, RTC_DEC
                    date: 0x1 - 0x31(BCD format)
                    day_of_week: RTC_MONDAY, RTC_TUESDAY, RTC_WEDSDAY, RTC_THURSDAY
                                     RTC_FRIDAY, RTC_SATURDAY, RTC_SUNDAY
                    hour: 0x0 - 0x12(BCD format) or 0x0 - 0x23(BCD format) depending on the rtc_display_format chose
                    minute: 0x0 - 0x59(BCD format)
                    second: 0x0 - 0x59(BCD format)
                    factor_asyn: 0x0 - 0x7F
                    factor_syn: 0x0 - 0x7FFF
                    am_pm: RTC_AM, RTC_PM
                    display_format: RTC_24HOUR, RTC_12HOUR
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_init(rtc_parameter_struct* rtc_initpara_struct)
  {
      ErrStatus error_status = ERROR;
      uint32_t reg_time = 0U, reg_date = 0U;
  
      reg_date = (DATE_YR(rtc_initpara_struct->year) | \
                  DATE_DOW(rtc_initpara_struct->day_of_week) | \
                  DATE_MON(rtc_initpara_struct->month) | \
                  DATE_DAY(rtc_initpara_struct->date)); 
      
      reg_time = (rtc_initpara_struct->am_pm| \
                  TIME_HR(rtc_initpara_struct->hour)  | \
                  TIME_MN(rtc_initpara_struct->minute) | \
                  TIME_SC(rtc_initpara_struct->second)); 
                
      /* 1st: disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      /* 2nd: enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){    
          RTC_PSC = (uint32_t)(PSC_FACTOR_A(rtc_initpara_struct->factor_asyn)| \
                               PSC_FACTOR_S(rtc_initpara_struct->factor_syn));
  
          RTC_TIME = (uint32_t)reg_time;
          RTC_DATE = (uint32_t)reg_date;
  
          RTC_CTL &= (uint32_t)(~RTC_CTL_CS);
          RTC_CTL |=  rtc_initpara_struct->display_format;
          
          /* 3rd: exit init mode */  
          rtc_init_mode_exit();
          
          /* 4th: wait the RSYNF flag to set */
          error_status = rtc_register_sync_wait();
      }
  
      /* 5th:  enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      enter RTC init mode
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_init_mode_enter(void)
  {
      volatile uint32_t time_index = RTC_INITM_TIMEOUT;
      uint32_t flag_status = RESET;
      ErrStatus error_status = ERROR;
  
      /* check whether it has been in init mode */
      if ((uint32_t)RESET == (RTC_STAT & RTC_STAT_INITF)){   
          RTC_STAT |= RTC_STAT_INITM;
          
          /* wait until the INITF flag to be set */
          do{
             flag_status = RTC_STAT & RTC_STAT_INITF;
          }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
  
          if ((uint32_t)RESET != flag_status){        
              error_status = SUCCESS;
          }
      }else{
          error_status = SUCCESS;
      }
      return error_status;
  }
  
  /*!
      \brief      exit RTC init mode
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void rtc_init_mode_exit(void)
  {
      RTC_STAT &= (uint32_t)(~RTC_STAT_INITM);
  }
  
  /*!
      \brief      wait until RTC_TIME and RTC_DATE registers are synchronized with APB clock, and the shadow 
                  registers are updated
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_register_sync_wait(void)
  {
      volatile uint32_t time_index = RTC_RSYNF_TIMEOUT;
      uint32_t flag_status = RESET;
      ErrStatus error_status = ERROR;
  
      if ((uint32_t)RESET == (RTC_CTL & RTC_CTL_BPSHAD)){
          /* disable the write protection */
          RTC_WPK = RTC_UNLOCK_KEY1;
          RTC_WPK = RTC_UNLOCK_KEY2;
  
          /* firstly clear RSYNF flag */
          RTC_STAT &= (uint32_t)(~RTC_STAT_RSYNF);
  
          /* wait until RSYNF flag to be set */
          do{
              flag_status = RTC_STAT & RTC_STAT_RSYNF;
          }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
  
          if ((uint32_t)RESET != flag_status){  
              error_status = SUCCESS;
          }
          
          /* enable the write protection */
          RTC_WPK = RTC_LOCK_KEY;
      }else{ 
          error_status = SUCCESS;
      }
  
      return error_status;
  }
  
  /*!
      \brief      get current time and date
      \param[in]  none
      \param[out] rtc_initpara_struct: pointer to a rtc_parameter_struct structure which contains 
                  parameters for initialization of the rtc peripheral
                  members of the structure and the member values are shown as below:
                    year: 0x0 - 0x99(BCD format)
                    month: RTC_JAN, RTC_FEB, RTC_MAR, RTC_APR, RTC_MAY, RTC_JUN,
                               RTC_JUL, RTC_AUG, RTC_SEP, RTC_OCT, RTC_NOV, RTC_DEC
                    date: 0x1 - 0x31(BCD format)
                    day_of_week: RTC_MONDAY, RTC_TUESDAY, RTC_WEDSDAY, RTC_THURSDAY
                                     RTC_FRIDAY, RTC_SATURDAY, RTC_SUNDAY
                    hour: 0x0 - 0x12(BCD format) or 0x0 - 0x23(BCD format) depending on the rtc_display_format chose
                    minute: 0x0 - 0x59(BCD format)
                    second: 0x0 - 0x59(BCD format)
                    factor_asyn: 0x0 - 0x7F
                    factor_syn: 0x0 - 0x7FFF
                    am_pm: RTC_AM, RTC_PM
                    display_format: RTC_24HOUR, RTC_12HOUR
      \retval     none
  */
  void rtc_current_time_get(rtc_parameter_struct* rtc_initpara_struct)
  {
      uint32_t temp_tr = 0U, temp_dr = 0U, temp_pscr = 0U, temp_ctlr = 0U;
  
      temp_tr = (uint32_t)RTC_TIME;   
      temp_dr = (uint32_t)RTC_DATE;
      temp_pscr = (uint32_t)RTC_PSC;
      temp_ctlr = (uint32_t)RTC_CTL;
    
      /* get current time and construct rtc_parameter_struct structure */
      rtc_initpara_struct->year = (uint8_t)GET_DATE_YR(temp_dr);
      rtc_initpara_struct->month = (uint8_t)GET_DATE_MON(temp_dr);
      rtc_initpara_struct->date = (uint8_t)GET_DATE_DAY(temp_dr);
      rtc_initpara_struct->day_of_week = (uint8_t)GET_DATE_DOW(temp_dr);  
      rtc_initpara_struct->hour = (uint8_t)GET_TIME_HR(temp_tr);
      rtc_initpara_struct->minute = (uint8_t)GET_TIME_MN(temp_tr);
      rtc_initpara_struct->second = (uint8_t)GET_TIME_SC(temp_tr);
      rtc_initpara_struct->factor_asyn = (uint16_t)GET_PSC_FACTOR_A(temp_pscr);
      rtc_initpara_struct->factor_syn = (uint16_t)GET_PSC_FACTOR_S(temp_pscr);
      rtc_initpara_struct->am_pm = (uint32_t)(temp_pscr & RTC_TIME_PM); 
      rtc_initpara_struct->display_format = (uint32_t)(temp_ctlr & RTC_CTL_CS);
  }
  
  /*!
      \brief      get current subsecond value
      \param[in]  none
      \param[out] none
      \retval     current subsecond value
  */
  uint32_t rtc_subsecond_get(void)
  {
      uint32_t reg = 0U;
      /* if BPSHAD bit is reset, reading RTC_SS will lock RTC_TIME and RTC_DATE automatically */
      reg = (uint32_t)RTC_SS;
      /* read RTC_DATE to unlock the 3 shadow registers */
      (void) (RTC_DATE);
  
      return reg;
  }
  
  /*!
      \brief      configure RTC alarm
      \param[in]  rtc_alarm: RTC_ALARM0 or RTC_ALARM1
      \param[in]  rtc_alarm_time: pointer to a rtc_alarm_struct structure which contains 
                  parameters for RTC alarm configuration
                  members of the structure and the member values are shown as below:
                    alarm_mask: RTC_ALARM_NONE_MASK, RTC_ALARM_DATE_MASK, RTC_ALARM_HOUR_MASK
                                    RTC_ALARM_MINUTE_MASK, RTC_ALARM_SECOND_MASK, RTC_ALARM_ALL_MASK
                    weekday_or_date: RTC_ALARM_DATE_SELECTED, RTC_ALARM_WEEKDAY_SELECTED
                    alarm_day: 1) 0x1 - 0x31(BCD format) if RTC_ALARM_DATE_SELECTED is set
                                   2) RTC_MONDAY, RTC_TUESDAY, RTC_WEDSDAY, RTC_THURSDAY, RTC_FRIDAY,
                                      RTC_SATURDAY, RTC_SUNDAY if RTC_ALARM_WEEKDAY_SELECTED is set
                    alarm_hour: 0x0 - 0x12(BCD format) or 0x0 - 0x23(BCD format) depending on the rtc_display_format
                    alarm_minute: 0x0 - 0x59(BCD format)
                    alarm_second: 0x0 - 0x59(BCD format)
                    am_pm: RTC_AM, RTC_PM
      \param[out] none
      \retval     none
  */
  void rtc_alarm_config(uint8_t rtc_alarm, rtc_alarm_struct* rtc_alarm_time)
  {
      uint32_t reg_alrmtd = 0U;
  
      reg_alrmtd =(rtc_alarm_time->alarm_mask | \
                   rtc_alarm_time->weekday_or_date | \
                   rtc_alarm_time->am_pm | \
                   ALRMTD_DAY(rtc_alarm_time->alarm_day) | \
                   ALRMTD_HR(rtc_alarm_time->alarm_hour) | \
                   ALRMTD_MN(rtc_alarm_time->alarm_minute) | \
                   ALRMTD_SC(rtc_alarm_time->alarm_second));
  
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      if(RTC_ALARM0 == rtc_alarm){
          RTC_ALRM0TD = (uint32_t)reg_alrmtd;
      
      }else{
          RTC_ALRM1TD = (uint32_t)reg_alrmtd;
      }
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      configure subsecond of RTC alarm
      \param[in]  rtc_alarm: RTC_ALARM0 or RTC_ALARM1
      \param[in]  mask_subsecond: alarm subsecond mask
        \arg        RTC_MASKSSC_0_14: mask alarm subsecond configuration
        \arg        RTC_MASKSSC_1_14: mask RTC_ALRMXSS_SSC[14:1], and RTC_ALRMXSS_SSC[0] is to be compared
        \arg        RTC_MASKSSC_2_14: mask RTC_ALRMXSS_SSC[14:2], and RTC_ALRMXSS_SSC[1:0] is to be compared
        \arg        RTC_MASKSSC_3_14: mask RTC_ALRMXSS_SSC[14:3], and RTC_ALRMXSS_SSC[2:0] is to be compared
        \arg        RTC_MASKSSC_4_14: mask RTC_ALRMXSS_SSC[14:4]], and RTC_ALRMXSS_SSC[3:0] is to be compared
        \arg        RTC_MASKSSC_5_14: mask RTC_ALRMXSS_SSC[14:5], and RTC_ALRMXSS_SSC[4:0] is to be compared
        \arg        RTC_MASKSSC_6_14: mask RTC_ALRMXSS_SSC[14:6], and RTC_ALRMXSS_SSC[5:0] is to be compared
        \arg        RTC_MASKSSC_7_14: mask RTC_ALRMXSS_SSC[14:7], and RTC_ALRMXSS_SSC[6:0] is to be compared
        \arg        RTC_MASKSSC_8_14: mask RTC_ALRMXSS_SSC[14:8], and RTC_ALRMXSS_SSC[7:0] is to be compared
        \arg        RTC_MASKSSC_9_14: mask RTC_ALRMXSS_SSC[14:9], and RTC_ALRMXSS_SSC[8:0] is to be compared
        \arg        RTC_MASKSSC_10_14: mask RTC_ALRMXSS_SSC[14:10], and RTC_ALRMXSS_SSC[9:0] is to be compared
        \arg        RTC_MASKSSC_11_14: mask RTC_ALRMXSS_SSC[14:11], and RTC_ALRMXSS_SSC[10:0] is to be compared
        \arg        RTC_MASKSSC_12_14: mask RTC_ALRMXSS_SSC[14:12], and RTC_ALRMXSS_SSC[11:0] is to be compared
        \arg        RTC_MASKSSC_13_14: mask RTC_ALRMXSS_SSC[14:13], and RTC_ALRMXSS_SSC[12:0] is to be compared
        \arg        RTC_MASKSSC_14: mask RTC_ALRMXSS_SSC[14], and RTC_ALRMXSS_SSC[13:0] is to be compared
        \arg        RTC_MASKSSC_NONE: mask none, and RTC_ALRMXSS_SSC[14:0] is to be compared
      \param[in]  subsecond: alarm subsecond value(0x000 - 0x7FFF)
      \param[out] none
      \retval     none
  */
  void rtc_alarm_subsecond_config(uint8_t rtc_alarm, uint32_t mask_subsecond, uint32_t subsecond)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;  
  
      if(RTC_ALARM0 == rtc_alarm){
          RTC_ALRM0SS = mask_subsecond | subsecond;  
      }else{
          RTC_ALRM1SS = mask_subsecond | subsecond; 
      }
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      get RTC alarm
      \param[in]  rtc_alarm: RTC_ALARM0 or RTC_ALARM1
      \param[out] rtc_alarm_time: pointer to a rtc_alarm_struct structure which contains 
                  parameters for RTC alarm configuration
                  members of the structure and the member values are shown as below:
                    alarm_mask: RTC_ALARM_NONE_MASK, RTC_ALARM_DATE_MASK, RTC_ALARM_HOUR_MASK
                                    RTC_ALARM_MINUTE_MASK, RTC_ALARM_SECOND_MASK, RTC_ALARM_ALL_MASK
                    weekday_or_date: RTC_ALARM_DATE_SELECTED, RTC_ALARM_WEEKDAY_SELECTED
                    alarm_day: 1) 0x1 - 0x31(BCD format) if RTC_ALARM_DATE_SELECTED is set
                                   2) RTC_MONDAY, RTC_TUESDAY, RTC_WEDSDAY, RTC_THURSDAY, RTC_FRIDAY,
                                      RTC_SATURDAY, RTC_SUNDAY if RTC_ALARM_WEEKDAY_SELECTED is set
                    alarm_hour: 0x0 - 0x12(BCD format) or 0x0 - 0x23(BCD format) depending on the rtc_display_format
                    alarm_minute: 0x0 - 0x59(BCD format)
                    alarm_second: 0x0 - 0x59(BCD format)
                    am_pm: RTC_AM, RTC_PM
      \retval     none
  */
  void rtc_alarm_get(uint8_t rtc_alarm, rtc_alarm_struct* rtc_alarm_time)
  {
      uint32_t reg_alrmtd = 0U;
  
      /* get the value of RTC_ALRM0TD register */
      if(RTC_ALARM0 == rtc_alarm){
          reg_alrmtd = RTC_ALRM0TD;
      }else{
          reg_alrmtd = RTC_ALRM1TD;
      }
      /* get alarm parameters and construct the rtc_alarm_struct structure */
      rtc_alarm_time->alarm_mask = reg_alrmtd & RTC_ALARM_ALL_MASK; 
      rtc_alarm_time->am_pm = (uint32_t)(reg_alrmtd & RTC_ALRMXTD_PM);
      rtc_alarm_time->weekday_or_date = (uint32_t)(reg_alrmtd & RTC_ALRMXTD_DOWS);
      rtc_alarm_time->alarm_day = (uint8_t)GET_ALRMTD_DAY(reg_alrmtd);
      rtc_alarm_time->alarm_hour = (uint8_t)GET_ALRMTD_HR(reg_alrmtd);
      rtc_alarm_time->alarm_minute = (uint8_t)GET_ALRMTD_MN(reg_alrmtd);
      rtc_alarm_time->alarm_second = (uint8_t)GET_ALRMTD_SC(reg_alrmtd);  
  }
  
  /*!
      \brief      get RTC alarm subsecond
      \param[in]  rtc_alarm: RTC_ALARM0 or RTC_ALARM1
      \param[out] none
      \retval     RTC alarm subsecond value
  */
  uint32_t rtc_alarm_subsecond_get(uint8_t rtc_alarm)
  {
      if(RTC_ALARM0 == rtc_alarm){
          return ((uint32_t)(RTC_ALRM0SS & RTC_ALRM0SS_SSC));
      }else{
          return ((uint32_t)(RTC_ALRM1SS & RTC_ALRM1SS_SSC));
      }
  }
  
  /*!
      \brief      enable RTC alarm
      \param[in]  rtc_alarm: RTC_ALARM0 or RTC_ALARM1
      \param[out] none
      \retval     none
  */
  void rtc_alarm_enable(uint8_t rtc_alarm)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      if(RTC_ALARM0 == rtc_alarm){
          RTC_CTL |= RTC_CTL_ALRM0EN;
      }else{
          RTC_CTL |= RTC_CTL_ALRM1EN;
      }
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      disable RTC alarm
      \param[in]  rtc_alarm: RTC_ALARM0 or RTC_ALARM1
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_alarm_disable(uint8_t rtc_alarm)
  {
      volatile uint32_t time_index = RTC_ALRMXWF_TIMEOUT;
      ErrStatus error_status = ERROR;
      uint32_t flag_status = RESET;
  
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      
      /* clear the state of alarm */
      if(RTC_ALARM0 == rtc_alarm){
          RTC_CTL &= (uint32_t)(~RTC_CTL_ALRM0EN); 
          /* wait until ALRM0WF flag to be set after the alarm is disabled */
          do{
              flag_status = RTC_STAT & RTC_STAT_ALRM0WF;
          }while((--time_index > 0U) && ((uint32_t)RESET == flag_status)); 
      }else{
          RTC_CTL &= (uint32_t)(~RTC_CTL_ALRM1EN);  
          /* wait until ALRM1WF flag to be set after the alarm is disabled */
          do{
              flag_status = RTC_STAT & RTC_STAT_ALRM1WF;
          }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
      }
    
      if ((uint32_t)RESET != flag_status){     
          error_status = SUCCESS;
      }
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      enable RTC time-stamp
      \param[in]  edge: specify which edge to detect of time-stamp
        \arg        RTC_TIMESTAMP_RISING_EDGE: rising edge is valid event edge for timestamp event
        \arg        RTC_TIMESTAMP_FALLING_EDGE: falling edge is valid event edge for timestamp event
      \param[out] none
      \retval     none
  */
  void rtc_timestamp_enable(uint32_t edge)
  {
      uint32_t reg_ctl = 0U;
  
      /* clear the bits to be configured in RTC_CTL */
      reg_ctl = (uint32_t)(RTC_CTL & (uint32_t)(~(RTC_CTL_TSEG | RTC_CTL_TSEN)));
  
      /* new configuration */
      reg_ctl |= (uint32_t)(edge | RTC_CTL_TSEN);
     
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      RTC_CTL = (uint32_t)reg_ctl;
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      disable RTC time-stamp
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void rtc_timestamp_disable(void)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      
      /* clear the TSEN bit */
      RTC_CTL &= (uint32_t)(~ RTC_CTL_TSEN);
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      get RTC timestamp time and date
      \param[in]  none
      \param[out] rtc_timestamp: pointer to a rtc_timestamp_struct structure which contains 
                  parameters for RTC time-stamp configuration
                  members of the structure and the member values are shown as below:
                    timestamp_month: RTC_JAN, RTC_FEB, RTC_MAR, RTC_APR, RTC_MAY, RTC_JUN,
                                         RTC_JUL, RTC_AUG, RTC_SEP, RTC_OCT, RTC_NOV, RTC_DEC
                    timestamp_date: 0x1 - 0x31(BCD format)
                    timestamp_day: RTC_MONDAY, RTC_TUESDAY, RTC_WEDSDAY, RTC_THURSDAY, RTC_FRIDAY,
                                       RTC_SATURDAY, RTC_SUNDAY if RTC_ALARM_WEEKDAY_SELECTED is set
                    timestamp_hour: 0x0 - 0x12(BCD format) or 0x0 - 0x23(BCD format) depending on the rtc_display_format
                    timestamp_minute: 0x0 - 0x59(BCD format)
                    timestamp_second: 0x0 - 0x59(BCD format)
                    am_pm: RTC_AM, RTC_PM
      \retval     none
  */
  void rtc_timestamp_get(rtc_timestamp_struct* rtc_timestamp)
  {
      uint32_t temp_tts = 0U, temp_dts = 0U;
  
      /* get the value of time_stamp registers */
      temp_tts = (uint32_t)RTC_TTS;
      temp_dts = (uint32_t)RTC_DTS;
    
      /* get timestamp time and construct the rtc_timestamp_struct structure */
      rtc_timestamp->am_pm = (uint32_t)(temp_tts & RTC_TTS_PM);
      rtc_timestamp->timestamp_month = (uint8_t)GET_DTS_MON(temp_dts);
      rtc_timestamp->timestamp_date = (uint8_t)GET_DTS_DAY(temp_dts);
      rtc_timestamp->timestamp_day = (uint8_t)GET_DTS_DOW(temp_dts);
      rtc_timestamp->timestamp_hour = (uint8_t)GET_TTS_HR(temp_tts);
      rtc_timestamp->timestamp_minute = (uint8_t)GET_TTS_MN(temp_tts);
      rtc_timestamp->timestamp_second = (uint8_t)GET_TTS_SC(temp_tts);
  }
  
  /*!
      \brief      get RTC time-stamp subsecond
      \param[in]  none
      \param[out] none
      \retval     RTC time-stamp subsecond value
  */
  uint32_t rtc_timestamp_subsecond_get(void)
  {
      return ((uint32_t)RTC_SSTS);
  }
  
  /*!
      \brief      RTC time-stamp mapping 
      \param[in]  rtc_af:
        \arg        RTC_AF0_TIMESTAMP: RTC_AF0 use for timestamp
        \arg        RTC_AF1_TIMESTAMP: RTC_AF1 use for timestamp
      \param[out] none
      \retval     none
  */
  void rtc_timestamp_pin_map(uint32_t rtc_af)
  {
      RTC_TAMP &= ~RTC_TAMP_TSSEL;
      RTC_TAMP |= rtc_af;
  }
  
  /*!
      \brief      enable RTC tamper
      \param[in]  rtc_tamper: pointer to a rtc_tamper_struct structure which contains 
                  parameters for RTC tamper configuration
                  members of the structure and the member values are shown as below:
                    detecting tamper event can using edge mode or level mode
                    (1) using edge mode configuration:
                    tamper_source: RTC_TAMPER0, RTC_TAMPER1
                    tamper_trigger: RTC_TAMPER_TRIGGER_EDGE_RISING, RTC_TAMPER_TRIGGER_EDGE_FALLING
                    tamper_filter: RTC_FLT_EDGE
                    tamper_with_timestamp: DISABLE, ENABLE
                    (2) using level mode configuration:
                    tamper_source: RTC_TAMPER0, RTC_TAMPER1
                    tamper_trigger:RTC_TAMPER_TRIGGER_LEVEL_LOW, RTC_TAMPER_TRIGGER_LEVEL_HIGH
                    tamper_filter: RTC_FLT_2S, RTC_FLT_4S, RTC_FLT_8S
                    tamper_sample_frequency: RTC_FREQ_DIV32768, RTC_FREQ_DIV16384, RTC_FREQ_DIV8192,
                                                 RTC_FREQ_DIV4096, RTC_FREQ_DIV2048, RTC_FREQ_DIV1024,
                                                 RTC_FREQ_DIV512, RTC_FREQ_DIV256
                    tamper_precharge_enable: DISABLE, ENABLE
                    tamper_precharge_time: RTC_PRCH_1C, RTC_PRCH_2C, RTC_PRCH_4C, RTC_PRCH_8C
                    tamper_with_timestamp: DISABLE, ENABLE
      \param[out] none
      \retval     none
  */
  void rtc_tamper_enable(rtc_tamper_struct* rtc_tamper)
  {
      /* disable tamper */
      RTC_TAMP &= (uint32_t)~(rtc_tamper->tamper_source); 
  
      /* tamper filter must be used when the tamper source is voltage level detection */
      RTC_TAMP &= (uint32_t)~RTC_TAMP_FLT;
      
      /* the tamper source is voltage level detection */
      if((uint32_t)(rtc_tamper->tamper_filter) != RTC_FLT_EDGE ){ 
          RTC_TAMP &= (uint32_t)~(RTC_TAMP_DISPU | RTC_TAMP_PRCH | RTC_TAMP_FREQ | RTC_TAMP_FLT);
  
          /* check if the tamper pin need precharge, if need, then configure the precharge time */
          if(DISABLE == rtc_tamper->tamper_precharge_enable){
              RTC_TAMP |=  (uint32_t)RTC_TAMP_DISPU;    
          }else{
              RTC_TAMP |= (uint32_t)(rtc_tamper->tamper_precharge_time);
          }
  
          RTC_TAMP |= (uint32_t)(rtc_tamper->tamper_sample_frequency);
          RTC_TAMP |= (uint32_t)(rtc_tamper->tamper_filter);
          
          /* configure the tamper trigger */
          RTC_TAMP &= ((uint32_t)~((rtc_tamper->tamper_source) << RTC_TAMPER_TRIGGER_POS));    
          if(RTC_TAMPER_TRIGGER_LEVEL_LOW != rtc_tamper->tamper_trigger){
              RTC_TAMP |= (uint32_t)((rtc_tamper->tamper_source)<< RTC_TAMPER_TRIGGER_POS);
          }
      }else{
   
          /* configure the tamper trigger */
          RTC_TAMP &= ((uint32_t)~((rtc_tamper->tamper_source) << RTC_TAMPER_TRIGGER_POS));    
          if(RTC_TAMPER_TRIGGER_EDGE_RISING != rtc_tamper->tamper_trigger){
              RTC_TAMP |= (uint32_t)((rtc_tamper->tamper_source)<< RTC_TAMPER_TRIGGER_POS);  
          }
      }
      
      RTC_TAMP &= (uint32_t)~RTC_TAMP_TPTS;      
      if(DISABLE != rtc_tamper->tamper_with_timestamp){           
          /* the tamper event also cause a time-stamp event */
          RTC_TAMP |= (uint32_t)RTC_TAMP_TPTS;
      }    
      /* enable tamper */
      RTC_TAMP |=  (uint32_t)(rtc_tamper->tamper_source); 
  }
  
  /*!
      \brief      disable RTC tamper
      \param[in]  source: specify which tamper source to be disabled
        \arg        RTC_TAMPER0
        \arg        RTC_TAMPER1
      \param[out] none
      \retval     none
  */
  void rtc_tamper_disable(uint32_t source)
  {
      /* disable tamper */
      RTC_TAMP &= (uint32_t)~source; 
  
  }
  
  /*!
      \brief      RTC tamper0 mapping 
      \param[in]  rtc_af:
        \arg        RTC_AF0_TAMPER0: RTC_AF0 use for tamper0
        \arg        RTC_AF1_TAMPER0: RTC_AF1 use for tamper0
      \param[out] none
      \retval     none
  */
  void rtc_tamper0_pin_map(uint32_t rtc_af)
  {
      RTC_TAMP &= ~(RTC_TAMP_TP0EN | RTC_TAMP_TP0SEL);
      RTC_TAMP |= rtc_af;
  }
  
  /*!
      \brief      enable specified RTC interrupt
      \param[in]  interrupt: specify which interrupt source to be enabled
        \arg        RTC_INT_TIMESTAMP: timestamp interrupt
        \arg        RTC_INT_ALARM0: alarm0 interrupt
        \arg        RTC_INT_ALARM1: alarm1 interrupt
        \arg        RTC_INT_TAMP: tamper detection interrupt
        \arg        RTC_INT_WAKEUP: wakeup timer interrupt
      \param[out] none
      \retval     none
  */
  void rtc_interrupt_enable(uint32_t interrupt)
  {  
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
   
      /* enable the interrupts in RTC_CTL register */
      RTC_CTL |= (uint32_t)(interrupt & (uint32_t)~RTC_TAMP_TPIE);
      /* enable the interrupts in RTC_TAMP register */
      RTC_TAMP |= (uint32_t)(interrupt & RTC_TAMP_TPIE);
      
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY; 
  }
  
  /*!
      \brief      disble specified RTC interrupt
      \param[in]  interrupt: specify which interrupt source to be disabled
        \arg        RTC_INT_TIMESTAMP: timestamp interrupt
        \arg        RTC_INT_ALARM0: alarm interrupt
        \arg        RTC_INT_ALARM1: alarm interrupt
        \arg        RTC_INT_TAMP: tamper detection interrupt
        \arg        RTC_INT_WAKEUP: wakeup timer interrupt
      \param[out] none
      \retval     none
  */
  void rtc_interrupt_disable(uint32_t interrupt)
  {  
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
   
      /* disable the interrupts in RTC_CTL register */
      RTC_CTL &= (uint32_t)~(interrupt & (uint32_t)~RTC_TAMP_TPIE);
      /* disable the interrupts in RTC_TAMP register */
      RTC_TAMP &= (uint32_t)~(interrupt & RTC_TAMP_TPIE);
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      check specified flag
      \param[in]  flag: specify which flag to check
        \arg        RTC_STAT_SCP: smooth calibration pending flag
        \arg        RTC_FLAG_TP1: RTC tamper 1 detected flag
        \arg        RTC_FLAG_TP0: RTC tamper 0 detected flag
        \arg        RTC_FLAG_TSOVR: time-stamp overflow flag
        \arg        RTC_FLAG_TS: time-stamp flag 
        \arg        RTC_FLAG_ALARM0: alarm0 occurs flag
        \arg        RTC_FLAG_ALARM1: alarm1 occurs flag
        \arg        RTC_FLAG_WT: wakeup timer occurs flag
        \arg        RTC_FLAG_INIT: initialization state flag
        \arg        RTC_FLAG_RSYN: register synchronization flag
        \arg        RTC_FLAG_YCM: year configuration mark status flag
        \arg        RTC_FLAG_SOP: shift function operation pending flag
        \arg        RTC_FLAG_ALRM0W: alarm0 configuration can be write flag
        \arg        RTC_FLAG_ALRM1W: alarm1 configuration can be write flag
        \arg        RTC_FLAG_WTW: wakeup timer can be write flag
      \param[out] none
      \retval     FlagStatus: SET or RESET
  */
  FlagStatus rtc_flag_get(uint32_t flag)
  {
      FlagStatus flag_state = RESET;
      
      if ((uint32_t)RESET != (RTC_STAT & flag)){
          flag_state = SET;
      }
      return flag_state;
  }
  
  /*!
      \brief      clear specified flag
        \arg        RTC_FLAG_TP1: RTC tamper 1 detected flag
        \arg        RTC_FLAG_TP0: RTC tamper 0 detected flag
        \arg        RTC_FLAG_TSOVR: time-stamp overflow flag
        \arg        RTC_FLAG_TS: time-stamp flag
        \arg        RTC_FLAG_WT: wakeup timer occurs flag
        \arg        RTC_FLAG_ALARM0: alarm0 occurs flag
        \arg        RTC_FLAG_ALARM1: alarm1 occurs flag
        \arg        RTC_FLAG_RSYN: register synchronization flag
      \param[out] none
      \retval     none
  */
  void rtc_flag_clear(uint32_t flag)
  {
      RTC_STAT &= (uint32_t)(~flag);  
  }
  
  /*!
      \brief      configure rtc alarm output source
      \param[in]  source: specify signal to output
        \arg        RTC_ALARM0_HIGH: when the  alarm0 flag is set, the output pin is high
        \arg        RTC_ALARM0_LOW: when the  alarm0 flag is set, the output pin is low
        \arg        RTC_ALARM1_HIGH: when the  alarm1 flag is set, the output pin is high
        \arg        RTC_ALARM1_LOW: when the  alarm1 flag is set, the output pin is low
        \arg        RTC_WAKEUP_HIGH: when the  wakeup flag is set, the output pin is high
        \arg        RTC_WAKEUP_LOW: when the  wakeup flag is set, the output pin is low
      \param[in]  mode: specify the output pin mode when output alarm signal
        \arg        RTC_ALARM_OUTPUT_OD: open drain mode
        \arg        RTC_ALARM_OUTPUT_PP: push pull mode
      \param[out] none
      \retval     none
  */
  void rtc_alarm_output_config(uint32_t source, uint32_t mode)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      RTC_CTL &= ~(RTC_CTL_OS | RTC_CTL_OPOL);
      RTC_TAMP &= ~RTC_TAMP_AOT;
  
      RTC_CTL |= (uint32_t)(source);
      /* alarm output */
      RTC_TAMP |= (uint32_t)(mode);
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      configure rtc calibration output source
      \param[in]  source: specify signal to output
        \arg        RTC_CALIBRATION_512HZ: when the LSE freqency is 32768Hz and the RTC_PSC 
                                           is the default value, output 512Hz signal
        \arg        RTC_CALIBRATION_1HZ: when the LSE freqency is 32768Hz and the RTC_PSC 
                                         is the default value, output 1Hz signal
      \param[out] none
      \retval     none
  */
  void rtc_calibration_output_config(uint32_t source)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      RTC_CTL &= (uint32_t)~(RTC_CTL_COEN | RTC_CTL_COS);
  
      RTC_CTL |= (uint32_t)(source);
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  
  /*!
      \brief      adjust the daylight saving time by adding or substracting one hour from the current time
      \param[in]  operation: hour adjustment operation
        \arg        RTC_CTL_A1H: add one hour
        \arg        RTC_CTL_S1H: substract one hour
      \param[out] none
      \retval     none
  */
  void rtc_hour_adjust(uint32_t operation)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      
      RTC_CTL |= (uint32_t)(operation);
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      adjust RTC second or subsecond value of current time
      \param[in]  add: add 1s to current time or not
        \arg        RTC_SHIFT_ADD1S_RESET: no effect
        \arg        RTC_SHIFT_ADD1S_SET: add 1s to current time
      \param[in]  minus: number of subsecond to minus from current time(0x0 - 0x7FFF)
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_second_adjust(uint32_t add, uint32_t minus)
  {
      volatile uint32_t time_index = RTC_SHIFTCTL_TIMEOUT;
      ErrStatus error_status = ERROR;
      uint32_t flag_status = RESET;
      uint32_t temp=0U;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      
      /* check if a shift operation is ongoing */    
      do{
          flag_status = RTC_STAT & RTC_STAT_SOPF;
      }while((--time_index > 0U) && ((uint32_t)RESET != flag_status));
      
      /* check if the function of reference clock detection is disabled */
      temp = RTC_CTL & RTC_CTL_REFEN;
      if((RESET == flag_status) && (RESET == temp)){  
          RTC_SHIFTCTL = (uint32_t)(add | SHIFTCTL_SFS(minus));
          error_status = rtc_register_sync_wait();        
      }
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      enable RTC bypass shadow registers function
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void rtc_bypass_shadow_enable(void)
  { 
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      RTC_CTL |= RTC_CTL_BPSHAD;
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      disable RTC bypass shadow registers function
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void rtc_bypass_shadow_disable(void)
  { 
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      RTC_CTL &= ~RTC_CTL_BPSHAD;
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      enable RTC reference clock detection function
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_refclock_detection_enable(void)
  {
      ErrStatus error_status = ERROR;
      
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      /* enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){
          RTC_CTL |= (uint32_t)RTC_CTL_REFEN;
          /* exit init mode */
          rtc_init_mode_exit();
      }
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      disable RTC reference clock detection function
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_refclock_detection_disable(void)
  {
      ErrStatus error_status = ERROR;
      
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
  
      /* enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){ 
          RTC_CTL &= (uint32_t)~RTC_CTL_REFEN;
          /* exit init mode */
          rtc_init_mode_exit();
      }
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      enable RTC auto wakeup function
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void rtc_wakeup_enable(void)
  {
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2; 
  
      RTC_CTL |= RTC_CTL_WTEN;
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  }
  
  /*!
      \brief      disable RTC auto wakeup function
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_wakeup_disable(void)
  {
      ErrStatus error_status = ERROR;
      volatile uint32_t time_index = RTC_WTWF_TIMEOUT;
      uint32_t flag_status = RESET;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      RTC_CTL &= ~RTC_CTL_WTEN;
      /* wait until the WTWF flag to be set */
      do{
          flag_status = RTC_STAT & RTC_STAT_WTWF;
      }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
  
      if ((uint32_t)RESET == flag_status){
          error_status = ERROR;
      }else{
          error_status = SUCCESS;
      }
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
      return error_status;
  }
  
  /*!
      \brief      set RTC auto wakeup timer clock
      \param[in]  wakeup_clock:
        \arg        WAKEUP_RTCCK_DIV16: RTC auto wakeup timer clock is RTC clock divided by 16 
        \arg        WAKEUP_RTCCK_DIV8: RTC auto wakeup timer clock is RTC clock divided by 8 
        \arg        WAKEUP_RTCCK_DIV4: RTC auto wakeup timer clock is RTC clock divided by 4 
        \arg        WAKEUP_RTCCK_DIV2: RTC auto wakeup timer clock is RTC clock divided by 2 
        \arg        WAKEUP_CKSPRE: RTC auto wakeup timer clock is ckspre
        \arg        WAKEUP_CKSPRE_2EXP16: RTC auto wakeup timer clock is ckspre and wakeup timer add 2exp16 
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_wakeup_clock_set(uint8_t wakeup_clock)
  {
      ErrStatus error_status = ERROR;
      volatile uint32_t time_index = RTC_WTWF_TIMEOUT;
      uint32_t flag_status = RESET;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2; 
      /* only when RTC_CTL_WTEN=0 and RTC_STAT_WTWF=1 can write RTC_CTL[2��0] */
      /* wait until the WTWF flag to be set */
      do{
          flag_status = RTC_STAT & RTC_STAT_WTWF;
      }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
  
      if ((uint32_t)RESET == flag_status){
          error_status = ERROR;
      }else{
          RTC_CTL &= (uint32_t)~ RTC_CTL_WTCS;
          RTC_CTL |= (uint32_t)wakeup_clock;
          error_status = SUCCESS;
      }
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
      
      return error_status;
  }
  
  /*!
      \brief      set wakeup timer value
      \param[in]  wakeup_timer: 0x0000-0xffff
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_wakeup_timer_set(uint16_t wakeup_timer)
  {
      ErrStatus error_status = ERROR;
      volatile uint32_t time_index = RTC_WTWF_TIMEOUT;
      uint32_t flag_status = RESET;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      /* wait until the WTWF flag to be set */
      do{
          flag_status = RTC_STAT & RTC_STAT_WTWF;
      }while((--time_index > 0U) && ((uint32_t)RESET == flag_status));
  
      if ((uint32_t)RESET == flag_status){
          error_status = ERROR;
      }else{
          RTC_WUT = (uint32_t)wakeup_timer;
          error_status = SUCCESS;
      }
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
      return error_status;
  }
  
  /*!
      \brief      get wakeup timer value
      \param[in]  none
      \param[out] none
      \retval     wakeup timer value
  */
   uint16_t rtc_wakeup_timer_get(void)
  {
      return (uint16_t)RTC_WUT;
  }
  
  /*!
      \brief      configure RTC smooth calibration
      \param[in]  window: select calibration window
        \arg        RTC_CALIBRATION_WINDOW_32S: 2exp20 RTCCLK cycles, 32s if RTCCLK = 32768 Hz
        \arg        RTC_CALIBRATION_WINDOW_16S: 2exp19 RTCCLK cycles, 16s if RTCCLK = 32768 Hz
        \arg        RTC_CALIBRATION_WINDOW_8S: 2exp18 RTCCLK cycles, 8s if RTCCLK = 32768 Hz
      \param[in]  plus: add RTC clock or not
        \arg        RTC_CALIBRATION_PLUS_SET: add one RTC clock every 2048 rtc clock
        \arg        RTC_CALIBRATION_PLUS_RESET: no effect
      \param[in]  minus: the RTC clock to minus during the calibration window(0x0 - 0x1FF)
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_smooth_calibration_config(uint32_t window, uint32_t plus, uint32_t minus)
  {
      volatile uint32_t time_index = RTC_HRFC_TIMEOUT;
      ErrStatus error_status = ERROR;
      uint32_t flag_status = RESET;
      
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;    
      
      /* check if a smooth calibration operation is ongoing */        
      do{
          flag_status = RTC_STAT & RTC_STAT_SCPF;
      }while((--time_index > 0U) && ((uint32_t)RESET != flag_status));
      
      if((uint32_t)RESET == flag_status){
          RTC_HRFC = (uint32_t)(window | plus | HRFC_CMSK(minus));
          error_status = SUCCESS;
      }
  
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
  
      return error_status;
  }
  
  /*!
      \brief      enable RTC coarse calibration
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_coarse_calibration_enable(void)
  {
      ErrStatus error_status = ERROR;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      /* enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){ 
          RTC_CTL |= (uint32_t)RTC_CTL_CCEN;
          /* exit init mode */
          rtc_init_mode_exit();
      }
      
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
      return error_status;
  }
  
  /*!
      \brief      disable RTC coarse calibration
      \param[in]  none
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_coarse_calibration_disable(void)
  {
      ErrStatus error_status = ERROR;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;    
      /* enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){ 
          RTC_CTL &= (uint32_t)~RTC_CTL_CCEN;
          /* exit init mode */
          rtc_init_mode_exit();
      }
      
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;	
      return error_status;
  }
  
  /*!
      \brief      config coarse calibration direction and step
      \param[in]  direction: CALIB_INCREASE or CALIB_DECREASE      
      \param[in]  step: 0x00-0x1F
                  COSD=0:
                    0x00:+0 PPM
                    0x01:+4 PPM
                    0x02:+8 PPM
                    ....
                    0x1F:+126 PPM
                  COSD=1:
                    0x00:-0 PPM
                    0x01:-2 PPM
                    0x02:-4 PPM
                    ....
                    0x1F:-63 PPM
      \param[out] none
      \retval     ErrStatus: ERROR or SUCCESS
  */
  ErrStatus rtc_coarse_calibration_config(uint8_t direction, uint8_t step)
  {
      ErrStatus error_status = ERROR;
      /* disable the write protection */
      RTC_WPK = RTC_UNLOCK_KEY1;
      RTC_WPK = RTC_UNLOCK_KEY2;
      
      /* enter init mode */
      error_status = rtc_init_mode_enter();
  
      if(ERROR != error_status){ 
          if(CALIB_DECREASE == direction){
              RTC_COSC |= (uint32_t)RTC_COSC_COSD;
          }else{
              RTC_COSC &= (uint32_t)~RTC_COSC_COSD;
          }
          RTC_COSC &= ~RTC_COSC_COSS;
          RTC_COSC |= (uint32_t)((uint32_t)step & 0x1FU);
          /* exit init mode */
          rtc_init_mode_exit();
      }
      
      /* enable the write protection */
      RTC_WPK = RTC_LOCK_KEY;
      
      return error_status;
  }
  