/*******************************************************************************
* Function Name  : RTC_Configuration
* Description    : Configures the RTC.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/

#include <stm32f10x_lib.h>              /* STM32F10x Library Definitions      */
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
//#define RTCClockSource_LSI   /* Use the internal 32 KHz oscillator as RTC clock source */
#define RTCClockSource_LSE   /* Use the external 32.768 KHz oscillator as RTC clock source */
//#define RTCClockOutput_Enable  /* RTC Clock/64 is output on tamper pin(PC.13) */
;

void SetupRTC(void)  {

/* Enable PWR and BKP clocks */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);
  
  /* Allow access to BKP Domain */
  PWR_BackupAccessCmd(ENABLE);

  /* Reset Backup Domain */
  BKP_DeInit();

#ifdef RTCClockSource_LSI
  /* Enable LSI */ 
  RCC_LSICmd(ENABLE);
  /* Wait till LSI is ready */
  while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)
  {
  }

  /* Select LSI as RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI);  
#elif defined	RTCClockSource_LSE  
  /* Enable LSE */
  RCC_LSEConfig(RCC_LSE_ON);
  /* Wait till LSE is ready */
  while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
  {
   }

  /* Select LSE as RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);  
#endif


  /* Enable RTC Clock */
  RCC_RTCCLKCmd(ENABLE);


#ifdef RTCClockOutput_Enable  
  /* Disable the Tamper Pin */
  BKP_TamperPinCmd(DISABLE); /* To output RTCCLK/64 on Tamper pin, the tamper
                               functionality must be disabled */
                               
  /* Enable RTC Clock Output on Tamper Pin */
  BKP_RTCCalibrationClockOutputCmd(ENABLE);
#endif 

  /* Wait for RTC registers synchronization */
  RTC_WaitForSynchro();

  /* Wait until last write operation on RTC registers has finished */
  RTC_WaitForLastTask();
  
  /* Enable the RTC Second */  
  RTC_ITConfig(RTC_IT_SEC, ENABLE);

  /* Wait until last write operation on RTC registers has finished */
  RTC_WaitForLastTask();
  
  /* Set RTC prescaler: set RTC period to 1sec */
#ifdef RTCClockSource_LSI
  RTC_SetPrescaler(31999); /* RTC period = RTCCLK/RTC_PR = (32.000 KHz)/(31999+1) */
#elif defined	RTCClockSource_LSE
  RTC_SetPrescaler(32767); /* RTC period = RTCCLK/RTC_PR = (32.768 KHz)/(32767+1) */
#endif
  
  /* Wait until last write operation on RTC registers has finished */
  RTC_WaitForLastTask();
}