stm32f0xx_rtc.c

stm32f0固件库

    if (RTC_WaitForSynchro() == ERROR)
    {
      status = ERROR;
    }
    else
    {
      status = SUCCESS;
    }

  }

  /* Enable the write protection for RTC registers */
  RTC->WPR = 0xFF;  

  return status;
}

/**
  * @brief  Initializes the RTC registers according to the specified parameters 
  *         in RTC_InitStruct.
  * @param  RTC_InitStruct: pointer to a RTC_InitTypeDef structure that contains 
  *         the configuration information for the RTC peripheral.
  * @note   The RTC Prescaler register is write protected and can be written in 
  *         initialization mode only.  
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: RTC registers are initialized
  *          - ERROR: RTC registers are not initialized  
  */
ErrorStatus RTC_Init(RTC_InitTypeDef* RTC_InitStruct)
{
  ErrorStatus status = ERROR;

  /* Check the parameters */
  assert_param(IS_RTC_HOUR_FORMAT(RTC_InitStruct->RTC_HourFormat));
  assert_param(IS_RTC_ASYNCH_PREDIV(RTC_InitStruct->RTC_AsynchPrediv));
  assert_param(IS_RTC_SYNCH_PREDIV(RTC_InitStruct->RTC_SynchPrediv));

  /* Disable the write protection for RTC registers */
  RTC->WPR = 0xCA;
  RTC->WPR = 0x53;

  /* Set Initialization mode */
  if (RTC_EnterInitMode() == ERROR)
  {
    status = ERROR;
  }
  else
  {
    /* Clear RTC CR FMT Bit */
    RTC->CR &= ((uint32_t)~(RTC_CR_FMT));
    /* Set RTC_CR register */
    RTC->CR |=  ((uint32_t)(RTC_InitStruct->RTC_HourFormat));
  
    /* Configure the RTC PRER */
    RTC->PRER = (uint32_t)(RTC_InitStruct->RTC_SynchPrediv);
    RTC->PRER |= (uint32_t)(RTC_InitStruct->RTC_AsynchPrediv << 16);

    /* Exit Initialization mode */
    RTC_ExitInitMode();

    status = SUCCESS;
  }
  /* Enable the write protection for RTC registers */
  RTC->WPR = 0xFF;

  return status;
}

/**
  * @brief  Fills each RTC_InitStruct member with its default value.
  * @param  RTC_InitStruct: pointer to a RTC_InitTypeDef structure which will be 
  *         initialized.
  * @retval None
  */
void RTC_StructInit(RTC_InitTypeDef* RTC_InitStruct)
{
  /* Initialize the RTC_HourFormat member */
  RTC_InitStruct->RTC_HourFormat = RTC_HourFormat_24;

  /* Initialize the RTC_AsynchPrediv member */
  RTC_InitStruct->RTC_AsynchPrediv = (uint32_t)0x7F;

  /* Initialize the RTC_SynchPrediv member */
  RTC_InitStruct->RTC_SynchPrediv = (uint32_t)0xFF; 
}

/**
  * @brief  Enables or disables the RTC registers write protection.
  * @note   All the RTC registers are write protected except for RTC_ISR[13:8], 
  *         RTC_TAFCR and RTC_BKPxR.
  * @note   Writing a wrong key reactivates the write protection.
  * @note   The protection mechanism is not affected by system reset.
  * @param  NewState: new state of the write protection.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void RTC_WriteProtectionCmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the write protection for RTC registers */
    RTC->WPR = 0xFF;
  }
  else
  {
    /* Disable the write protection for RTC registers */
    RTC->WPR = 0xCA;
    RTC->WPR = 0x53;
  }
}

/**
  * @brief  Enters the RTC Initialization mode.
  * @note   The RTC Initialization mode is write protected, use the 
  *         RTC_WriteProtectionCmd(DISABLE) before calling this function.
  * @param  None
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: RTC is in Init mode
  *          - ERROR: RTC is not in Init mode
  */
ErrorStatus RTC_EnterInitMode(void)
{
  __IO uint32_t initcounter = 0x00;
  ErrorStatus status = ERROR;
  uint32_t initstatus = 0x00;

  /* Check if the Initialization mode is set */
  if ((RTC->ISR & RTC_ISR_INITF) == (uint32_t)RESET)
  {
    /* Set the Initialization mode */
    RTC->ISR = (uint32_t)RTC_INIT_MASK;
    
    /* Wait till RTC is in INIT state and if Time out is reached exit */
    do
    {
      initstatus = RTC->ISR & RTC_ISR_INITF;
      initcounter++;  
    } while((initcounter != INITMODE_TIMEOUT) && (initstatus == 0x00));
    
    if ((RTC->ISR & RTC_ISR_INITF) != RESET)
    {
      status = SUCCESS;
    }
    else
    {
      status = ERROR;
    }
  }
  else
  {
    status = SUCCESS;
  }

  return (status);
}

/**
  * @brief  Exits the RTC Initialization mode.
  * @note   When the initialization sequence is complete, the calendar restarts 
  *         counting after 4 RTCCLK cycles.  
  * @note   The RTC Initialization mode is write protected, use the 
  *         RTC_WriteProtectionCmd(DISABLE) before calling this function.      
  * @param  None
  * @retval None
  */
void RTC_ExitInitMode(void)
{
  /* Exit Initialization mode */
  RTC->ISR &= (uint32_t)~RTC_ISR_INIT;
}

/**
  * @brief  Waits until the RTC Time and Date registers (RTC_TR and RTC_DR) are 
  *         synchronized with RTC APB clock.
  * @note   The RTC Resynchronization mode is write protected, use the 
  *         RTC_WriteProtectionCmd(DISABLE) before calling this function. 
  * @note   To read the calendar through the shadow registers after Calendar 
  *         initialization, calendar update or after wakeup from low power modes 
  *         the software must first clear the RSF flag. 
  *         The software must then wait until it is set again before reading 
  *         the calendar, which means that the calendar registers have been 
  *         correctly copied into the RTC_TR and RTC_DR shadow registers.   
  * @param  None
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: RTC registers are synchronised
  *          - ERROR: RTC registers are not synchronised
  */
ErrorStatus RTC_WaitForSynchro(void)
{
  __IO uint32_t synchrocounter = 0;
  ErrorStatus status = ERROR;
  uint32_t synchrostatus = 0x00;

  if ((RTC->CR & RTC_CR_BYPSHAD) != RESET)
  {
    /* Bypass shadow mode */
    status = SUCCESS;
  }
  else
  {
    /* Disable the write protection for RTC registers */
    RTC->WPR = 0xCA;
    RTC->WPR = 0x53;

    /* Clear RSF flag */
    RTC->ISR &= (uint32_t)RTC_RSF_MASK;

    /* Wait the registers to be synchronised */
    do
    {
      synchrostatus = RTC->ISR & RTC_ISR_RSF;
      synchrocounter++;  
    } while((synchrocounter != SYNCHRO_TIMEOUT) && (synchrostatus == 0x00));

    if ((RTC->ISR & RTC_ISR_RSF) != RESET)
    {
      status = SUCCESS;
    }
    else
    {
      status = ERROR;
    }

    /* Enable the write protection for RTC registers */
    RTC->WPR = 0xFF;
  }

  return (status);
}

/**
  * @brief  Enables or disables the RTC reference clock detection.
  * @param  NewState: new state of the RTC reference clock.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: RTC reference clock detection is enabled
  *          - ERROR: RTC reference clock detection is disabled  
  */
ErrorStatus RTC_RefClockCmd(FunctionalState NewState)
{
  ErrorStatus status = ERROR;

  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  /* Disable the write protection for RTC registers */
  RTC->WPR = 0xCA;
  RTC->WPR = 0x53;

  /* Set Initialization mode */
  if (RTC_EnterInitMode() == ERROR)
  {
    status = ERROR;
  }
  else
  {
    if (NewState != DISABLE)
    {
      /* Enable the RTC reference clock detection */
      RTC->CR |= RTC_CR_REFCKON;
    }
    else
    {
      /* Disable the RTC reference clock detection */
      RTC->CR &= ~RTC_CR_REFCKON;
    }
    /* Exit Initialization mode */
    RTC_ExitInitMode();

    status = SUCCESS;
  }

  /* Enable the write protection for RTC registers */
  RTC->WPR = 0xFF;

  return status;
}

/**
  * @brief  Enables or Disables the Bypass Shadow feature.
  * @note   When the Bypass Shadow is enabled the calendar value are taken 
  *         directly from the Calendar counter.
  * @param  NewState: new state of the Bypass Shadow feature.
  *         This parameter can be: ENABLE or DISABLE.
  * @retval None
*/
void RTC_BypassShadowCmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  /* Disable the write protection for RTC registers */
  RTC->WPR = 0xCA;
  RTC->WPR = 0x53;
  
  if (NewState != DISABLE)
  {
    /* Set the BYPSHAD bit */
    RTC->CR |= (uint8_t)RTC_CR_BYPSHAD;
  }
  else
  {
    /* Reset the BYPSHAD bit */
    RTC->CR &= (uint8_t)~RTC_CR_BYPSHAD;
  }

  /* Enable the write protection for RTC registers */
  RTC->WPR = 0xFF;
}

/**
  * @}
  */

/** @defgroup RTC_Group2 Time and Date configuration functions
 *  @brief   Time and Date configuration functions
 *
@verbatim
 ===============================================================================
               ##### Time and Date configuration functions #####
 ===============================================================================
    [..]  This section provide functions allowing to program and read the RTC
          Calendar (Time and Date).

@endverbatim
  * @{
  */

/**
  * @brief  Set the RTC current time.
  * @param  RTC_Format: specifies the format of the entered parameters.
  *   This parameter can be  one of the following values:
  *     @arg RTC_Format_BIN:  Binary data format 
  *     @arg RTC_Format_BCD:  BCD data format
  * @param  RTC_TimeStruct: pointer to a RTC_TimeTypeDef structure that contains 
  *                        the time configuration information for the RTC.
  * @retval An ErrorStatus enumeration value:
  *          - SUCCESS: RTC Time register is configured