我是按照STM32F4官方库的例程改的，当时钟源为LSI的时候可以正常的初始化，正常的读时间，但是一旦用了LSE始终之后初始化就会失败，RTC_Init(&RTC_InitStructure)返回值是ERROR，请问一下为什么，哦，对了，配置HSE也是不好使。下面贴源码：
void RTC_Config(void)
{
RTC_TimeTypeDef  RTC_TimeStructure;
RTC_InitTypeDef  RTC_InitStructure;
RTC_AlarmTypeDef RTC_AlarmStructure;

__IO uint32_t uwAsynchPrediv = 0xFF;
__IO uint32_t uwSynchPrediv  = 0x7F;

RTC_DateTypeDef RTC_DateStructure;
  
  /* Enable the PWR clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  /* Allow access to RTC */
  PWR_BackupAccessCmd(ENABLE);

// RCC_LSICmd(ENABLE);
RCC_LSEConfig(RCC_LSE_ON);

  /* Wait till LSI is ready */  
//  while(RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)
//  {
//  }
while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
  {
  }
  /* Select the RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);
RCC_RTCCLKCmd(ENABLE);

//????????
  RTC_WaitForSynchro();
  
  /* Configure the RTC data register and RTC prescaler */
  RTC_InitStructure.RTC_AsynchPrediv = uwAsynchPrediv;
  RTC_InitStructure.RTC_SynchPrediv = uwSynchPrediv;
  RTC_InitStructure.RTC_HourFormat = RTC_HourFormat_24;
//  RTC_Init(&RTC_InitStructure);
if(!RTC_Init(&RTC_InitStructure))
{
printf("init failed ");
}
  
//  /* Set the alarm 05h:20min:30s */
//  RTC_AlarmStructure.RTC_AlarmTime.RTC_H12     = RTC_H12_AM;
//  RTC_AlarmStructure.RTC_AlarmTime.RTC_Hours   = 0x00;
//  RTC_AlarmStructure.RTC_AlarmTime.RTC_Minutes = 0x00;
//  RTC_AlarmStructure.RTC_AlarmTime.RTC_Seconds = 0x00;
//  RTC_AlarmStructure.RTC_AlarmDateWeekDay = 0x24;
//  RTC_AlarmStructure.RTC_AlarmDateWeekDaySel   = RTC_AlarmDateWeekDaySel_Date;
//  RTC_AlarmStructure.RTC_AlarmMask = RTC_AlarmMask_DateWeekDay;
//  
//  /* Configure the RTC Alarm A register */
//  RTC_SetAlarm(RTC_Format_BCD, RTC_Alarm_A, &RTC_AlarmStructure);
//  
//  /* Enable RTC Alarm A Interrupt */
//  RTC_ITConfig(RTC_IT_ALRA, ENABLE);
//  
//  //????????A
//  RTC_AlarmCmd(RTC_Alarm_A, ENABLE);
//  
// //????????A±ê????
//  RTC_ClearFlag(RTC_FLAG_ALRAF);
  
  /* Set the date: Friday January 11th 2013 */
  RTC_DateStructure.RTC_Year = 0x15;
  RTC_DateStructure.RTC_Month = RTC_Month_September;
  RTC_DateStructure.RTC_Date = 0x24;
  RTC_DateStructure.RTC_WeekDay = RTC_Weekday_Thursday;
//  RTC_SetDate(RTC_Format_BCD, &RTC_DateStructure);
if(!RTC_SetDate(RTC_Format_BCD, &RTC_DateStructure))
{
printf("SetDate error");
}
  
  /* Set the time to 05h 20mn 00s AM */
  RTC_TimeStructure.RTC_H12     = RTC_H12_AM;
  RTC_TimeStructure.RTC_Hours   = 0x23;
  RTC_TimeStructure.RTC_Minutes = 0x40;
  RTC_TimeStructure.RTC_Seconds = 0x00; 
  
//  RTC_SetTime(RTC_Format_BCD, &RTC_TimeStructure);  
if(!RTC_SetTime(RTC_Format_BCD, &RTC_TimeStructure))
{
printf("SetTime error");
}
  
  /* Indicator for the RTC configuration */
  RTC_WriteBackupRegister(RTC_BKP_DR0, 0x15f3);

}
int main(void)
{
RTC_DateTypeDef RTC_DateTypeInstructure; 
RTC_TimeTypeDef RTC_TimeTypeInstructure;

systickinit();

// usart3config();
//
// usart2config();
//
// uart4config();

usart1config();


if(RTC_ReadBackupRegister(RTC_BKP_DR0) != 0x12f3)
{
RTC_Config();
printf("????RTC");
}
else
{
while(1)
{
delay(1000);
RTC_GetDate(RTC_Format_BCD,&RTC_DateTypeInstructure);
RTC_GetTime(RTC_Format_BCD,&RTC_TimeTypeInstructure);
printf("20%-2.2X?ê %X?? %X?? ????%X %X???± %X·? %X?? ",RTC_DateTypeInstructure.RTC_Year, 
RTC_DateTypeInstructure.RTC_Month,RTC_DateTypeInstructure.RTC_Date,RTC_DateTypeInstructure.RTC_WeekDay,
RTC_TimeTypeInstructure.RTC_Hours,RTC_TimeTypeInstructure.RTC_Minutes,RTC_TimeTypeInstructure.RTC_Seconds);
}
}
while(1)
{
delay(1000);
RTC_GetDate(RTC_Format_BCD,&RTC_DateTypeInstructure);
RTC_GetTime(RTC_Format_BCD,&RTC_TimeTypeInstructure);
printf("20%-2.2X?ê %X?? %X?? ????%X %X???± %X·? %X?? ",RTC_DateTypeInstructure.RTC_Year, 
RTC_DateTypeInstructure.RTC_Month,RTC_DateTypeInstructure.RTC_Date,RTC_DateTypeInstructure.RTC_WeekDay,
RTC_TimeTypeInstructure.RTC_Hours,RTC_TimeTypeInstructure.RTC_Minutes,RTC_TimeTypeInstructure.RTC_Seconds);
}
}