STM32F103C8 HSE OSC更换外部晶振后的配置

 

所使用庫：

使用STDPeriPh_Driver lib

目的：

將外部晶振8MHz改爲16MHz。

過程：

1 stm32f10x.h 中找HSE_VALUE 

/**
 * @brief In the following line adjust the value of External High Speed oscillator (HSE)
   used in your application 
   
   Tip: To avoid modifying this file each time you need to use different HSE, you
        can define the HSE value in your toolchain compiler preprocessor.
  */           
#if !defined  HSE_VALUE
 #ifdef STM32F10X_CL   
  #define HSE_VALUE    ((uint32_t)25000000) /*!< Value of the External oscillator in Hz */
 #else 
  #define HSE_VALUE    ((uint32_t)8000000) /*!< Value of the External oscillator in Hz */
 #endif /* STM32F10X_CL */
#endif /* HSE_VALUE */

 #define HSE_VALUE    ((uint32_t)8000000) /*!< Value of the External oscillator in Hz */

更改為:

 #define HSE_VALUE    ((uint32_t)16000000) /*!< Value of the External oscillator in Hz */

 

 2 system_stm32f10x.c 更改 配置 static void SetSysClockTo72(void)：

 

RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLMULL9);

 更改为：

RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLXTPRE_HSE_Div2 | RCC_CFGR_PLLMULL9);

    RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE |
                                        RCC_CFGR_PLLMULL));
//  8MHz HSE OSC;    RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLMULL9);
//  16MHz HSE OSC;
		RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSE | RCC_CFGR_PLLXTPRE_HSE_Div2 | RCC_CFGR_PLLMULL9);

 

Others

 

void SystemInit (void)

>>  SetSysClock();

>>SetSysClockTo72();

 

 

 

RTC CLK use LSI 40KHz

/*******************************************************************************
* Function Name  : NVIC_Configuration
* Description    : Configures the RTC.
* Input          : None
* Output         : None
* Return         : None
* Attention		 : None
*******************************************************************************/
static 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();
}

改为：

static 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 */
  //liushi RCC_LSEConfig(RCC_LSE_ON);

  /* Wait till LSE is ready */
  //liushi while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
  {}

  /* Select LSE as RTC Clock Source */
  //liushi RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);
  
	RCC_LSICmd(ENABLE); //liushi add 
		
		/* Wait till LSI is ready */
  while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) //liushi add
  {}
		
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI); //liushi add
		
		
  /* 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();
}