STM32學(xué)習筆記——RCC系統時(shí)鐘配置

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);//配置系統時(shí)鐘為PLL

while(RCC_GetSYSCLKSource()!=0x08)//檢查系統時(shí)鐘是否為PLL

{

}

}

else

{

while(1)

{

}

}

}

voidSetSysClockTo36(void)//設置系統時(shí)鐘為36MHz函數

{

RCC_DeInit();

RCC_HSEConfig(RCC_HSE_ON);

HSEStartUpStatus=RCC_WaitForHSEStartUp();

if(HSEStartUpStatus==SUCCESS)

{

FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

FLASH_SetLatency(FLASH_Latency_1);

RCC_HCLKConfig(RCC_SYSCLK_Div1);

RCC_PCLK2Config(RCC_HCLK_Div1);

RCC_PCLK1Config(RCC_HCLK_Div1);

RCC_PLLConfig(RCC_PLLSource_HSE_Div2,RCC_PLLMul_9);//8/2*9=36設置PLL為36MHz

RCC_PLLCmd(ENABLE);

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY)==RESET)

{

}

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

while(RCC_GetSYSCLKSource()!=0x08)

{

}

}

else

{

while(1)

{

}

}

}

voidSetSysClockTo48(void)//設置系統時(shí)鐘為48MHz函數

{

RCC_DeInit();

RCC_HSEConfig(RCC_HSE_ON);

HSEStartUpStatus=RCC_WaitForHSEStartUp();

if(HSEStartUpStatus==SUCCESS)

{

FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

FLASH_SetLatency(FLASH_Latency_1);

RCC_HCLKConfig(RCC_SYSCLK_Div1);

RCC_PCLK2Config(RCC_HCLK_Div1);

RCC_PCLK1Config(RCC_HCLK_Div2);

RCC_PLLConfig(RCC_PLLSource_HSE_Div1,RCC_PLLMul_6);//設置ＰＬＬ為４８ＭＨｚ

RCC_PLLCmd(ENABLE);

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY)==RESET)

{

}

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

while(RCC_GetSYSCLKSource()!=0x08)

{

}

}

else

{

while(1)

{

}

}

}

voidSetSysClockTo72(void)//設置系統時(shí)鐘為72MHz

{

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);//設置PLL為72MHz

RCC_PLLCmd(ENABLE);

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY)==RESET)

{

}

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

while(RCC_GetSYSCLKSource()!=0x08)

{

}

}

else

{

while(1)

{

}

}

}

voidNVIC_Configuration(void)//設置中斷向量表基址

{

NVIC_InitTypeDefNVIC_InitStructure;//NVIC初始化結構體，定義初始化ＮＶＩＣ的結構體變量

#ifdefVECT_TAB_RAM

NVIC_SetVectorTable(NVIC_VectTab_RAM,0x0);

#else

NVIC_SetVectorTable(NVIC_VectTab_FLASH,0x0);

#endif

//NVIC_InitStructure是前面定義的ＮＶＩＣ初始化結構體包括以下幾項

NVIC_InitStructure.NVIC_IRQChannel=RCC_IRQChannel;//指定IRQ通道這里指定為RCC全局中斷

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;//該參數設置成員NVIC_IRQChannel中的先占優(yōu)先級

NVIC_InitStructure.NVIC_IRQChannelSubPriority=0;//該參數設置成員NVIC_IRQChannel中的從優(yōu)先級詳見(jiàn)函數說(shuō)明P167

NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;//該參數指定在成員NVIC_IRQChannel中定義的IRQ通道被使能還是失能

//取值可以為ENABLE或DISABLE

NVIC_Init(&NVIC_InitStructure);//根據結構體NVIC_InitStructure中指定的參數初始化外設NVIC

}

voidDelay(vu32nCount)

{

for(;nCount!=0;nCount--);

}

#ifdefDEBUG

//assert_failed編寫(xiě)于文件main.c或其他用戶(hù)C文件中

voidassert_failed(u8*file,u32line)

{

while(1)

{

}

}

#endif