STM32???RCC???????
STM32?ж?????????????
HSI:????????????????????????????????????????????
HSE???????????????????????????????PLL????????????
LSE??????????????????????RTC?????RTC?????????
LSI????????????????????????????IWDGCLK
?????????????
STM32?и?????鶼??????????????????????????????????????????
????????????????3.3.0
??????????????????????
void RCC_Configuration(void)
{
ErrorStatus HSEStartUpStatus;
//SystemInit(); //???????????????????????????????????
RCC_DeInit(); //??λRCC????????,??λ?????
RCC_HSEConfig(RCC_HSE_ON); //????HSE???,??????HSE????????PLL??????
HSEStartUpStatus = RCC_WaitForHSEStartUp(); //???HSE??????
if(HSEStartUpStatus == SUCCESS) //???HSE???????
{
FLASH_PrefetchBufferCmd(ENABLE); //????FLASH????????
FLASH_SetLatency(FLASH_Latency_2); //FLASH???2???????????????????????????
RCC_HCLKConfig(RCC_SYSCLK_Div1); //????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); //????PLL
while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY)==RESET)
{} //???PLL???????
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); //?????????
while(RCC_GetSYSCLKSource() !=0x80) //??????HSE 9?????????????
{}
}
}
????????????
1.??RCC?????????????????? RCC_DeInit
2.??????????????HSE RCC_HSEConfig(RCC_HSE_ON);
3.????????????????? HSEStartUpStatus = RCC_WaitForHSEStartUp();
4.????AHB??? RCC_HCLKConfig;
5.???????APB2??? RCC_PCLK2Config;
6.?????????APB1??? RCC_PCLK1Config
7.????PLL RCC_PLLConfig
8.??PLL RCC_PLLCmd(ENABLE);
9.???PLL???? while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
10.????????? RCC_SYSCLKConfig
11.?ж????PLL??????? while(RCC_GetSYSCLKSource() != 0x08)
12.?????????????? RCC_APB2PeriphClockCmd()/RCC_APB1PeriphClockCmd????
??????????STM32??????????ú?????????72MHz??APH 72MHz??APB2 72MHz??APB1 32MHz??USB 48MHz
????????ADC???????ò????????????????????????????????STM32??????????????????????????д??
????admin ?????????2018-12-27
