#ifndef __SYS_H
#define __SYS_H	    		 
//系統(tǒng)時(shí)鐘初始化
//使用外部8M晶振,PLL到72M頻率		    
//正點(diǎn)原子@SCUT
//2008/12/14 
//V1.2
//不能在這里執(zhí)行所有外設(shè)復(fù)位!否則至少引起串口不工作.

#define uint unsigned int
#define uchar unsigned char	   

//把所有時(shí)鐘寄存器復(fù)位
void MYRCC_DeInit(void)
{										  					   
	RCC->APB1RSTR = 0x00000000;//復(fù)位結(jié)束			 
	RCC->APB2RSTR = 0x00000000; 
	  
  	RCC->AHBENR = 0x00000014;  //flash時(shí)鐘,閃存時(shí)鐘使能.DMA時(shí)鐘關(guān)閉	  
  	RCC->APB2ENR = 0x00000000; //外設(shè)時(shí)鐘關(guān)閉.			   
  	RCC->APB1ENR = 0x00000000;   
	RCC->CR |= 0x00000001;     //使能內(nèi)部高速時(shí)鐘HSION	 															 
	RCC->CFGR &= 0xF8FF0000;   //復(fù)位SW[1:0],HPRE[3:0],PPRE1[2:0],PPRE2[2:0],ADCPRE[1:0],MCO[2:0]					 
	RCC->CR &= 0xFEF6FFFF;     //復(fù)位HSEON,CSSON,PLLON
	RCC->CR &= 0xFFFBFFFF;     //復(fù)位HSEBYP	   	  
	RCC->CFGR &= 0xFF80FFFF;   //復(fù)位PLLSRC, PLLXTPRE, PLLMUL[3:0] and USBPRE 
	RCC->CIR = 0x00000000;     //關(guān)閉所有中斷
					  
#ifdef  VECT_TAB_RAM
	NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
#else  /* VECT_TAB_FLASH  */
	NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
#endif
}

//外部8M,則得到72M的系統(tǒng)時(shí)鐘	
void Stm32_Clock_Init(void)
{
	unsigned char temp=0;   
	MYRCC_DeInit();
	RCC->CR|=0x00010000;  //外部高速時(shí)鐘使能HSEON
	while(!(RCC->CR>>17));//等待外部時(shí)鐘就緒
	RCC->CFGR=0X1C0400;   //APB1/2=DIV2;AHB=DIV1;PLL=9*CLK;
	RCC->CFGR|=1<<16;	  //PLLSRC ON 
	FLASH->ACR|=0x32;	  //FLASH 2個(gè)延時(shí)周期

	RCC->CR|=0x01000000;  //PLLON
	while(!(RCC->CR>>25));//等待PLL鎖定
	RCC->CFGR|=0x00000002;//PLL作為系統(tǒng)時(shí)鐘	 
	while(temp!=0x02)     //等待PLL作為系統(tǒng)時(shí)鐘設(shè)置成功
	{   
		temp=RCC->CFGR>>2;
		temp&=0x03;
	}    
}
#endif