我用的是12.5P的晶振,也老是出现上电赶振难的问题.原来想换6P的,但是太难找.通达了解晶振参数.12.5P的晶振赶振到稳定比6P的晶振所需时间长.
而是我对RTC的初始化作而下调整:
这是Keil中RTC例程上修改
/*******************************************************************************
* Function Name : RTC_Configuration
* Description : Configures the RTC.
* Input : None
* Output : None
* Return : None
*******************************************************************************/
void RTC_Configuration(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();
/* 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);
/* Enable RTC Clock */
RCC_RTCCLKCmd(ENABLE);
/* 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 */
RTC_SetPrescaler(32767); /* RTC period = RTCCLK/RTC_PR = (32.768 KHz)/(32767+1) */
/* Wait until last write operation on RTC registers has finished */
RTC_WaitForLastTask();
}
将/* Enable LSE */
RCC_LSEConfig(RCC_LSE_ON);
/* Wait till LSE is ready */
while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
{
}
改动为:
u32 delay;
do
{
for(delay = 0;delay < 90000;delay++);
RCC_LSEConfig(RCC_LSE_ON);
}while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
现已很好的工作了.已测试好几天从没有再发生上电难振,每次都可以OK.但改回原来的方式则问题又再出现,大家可以试一试. |
