void SysClock_Init(void)
{
ErrorStatus HSEStartUpStatus;
RCC_DeInit();
RCC_HSEConfig(RCC_HSE_ON);
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if(HSEStartUpStatus == SUCCESS){
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
FLASH_SetLatency(FLASH_Latency_2);
RCC_HCLKConfig(RCC_SYSCLK_Div1);
RCC_PCLK2Config(RCC_HCLK_Div1);
RCC_PCLK1Config(RCC_HCLK_Div2);
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);
RCC_PLLCmd(ENABLE);
while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET){
;
}
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
while(RCC_GetSYSCLKSource() != 0x08){
;
}
}
}这些是干嘛用的呢 |