[应用相关] STM32之RCC

void RCC_Configuration(void)

{

         ErrorStatus HSEStartUpStatus;

         //SystemInit();                                                    //完全可以使用此函数配置，但是为了学习咱先不用

         RCC_DeInit();                                                      //复位RCC模块的寄存器,复位成缺省值

         RCC_HSEConfig(RCC_HSE_ON);                           //开启HSE时钟,咱是用HSE的时钟作为PLL的时钟源

         HSEStartUpStatus = RCC_WaitForHSEStartUp(); //获取HSE启动状态



         if(HSEStartUpStatus == SUCCESS)                      //如果HSE启动成功

        {

                  FLASH_PrefetchBufferCmd(ENABLE);          //开启FLASH的预取功能

                  FLASH_SetLatency(FLASH_Latency_2);      //FLASH延迟2个周期（这里我也不明白，先用吧）

   

                 RCC_HCLKConfig(RCC_SYSCLK_Div1);        //配置HCLK,PCLK2,PCLK1,PLL

                 RCC_PCLK2Config(RCC_HCLK_Div1);

                 RCC_PCLK1Config(RCC_HCLK_Div2);



                 RCC_PLLConfig(RCC_PLLSource_HSE_Div1,RCC_PLLMul_9);

                 RCC_PLLCmd(ENABLE);                              //启动PLL

                 while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY)==RESET)



                 {}                                                              //等待PLL启动完成

                 RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);  //配置系统时钟

                 while(RCC_GetSYSCLKSource() !=0x80)          //检查是否将HSE 9倍频后作为系统时钟



                 {} 

         }



}