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SYSCLK=72mhz

#include "main.h"
GPIO_InitTypeDef GPIO_InitStructure;
void mysysint()//系统初始化程序
{
ErrorStatus HSEStartUpStatus;//说明标志位
 RCC_DeInit();//所有外设全部缺省设置

/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready and if Time out is reached exit */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if(HSEStartUpStatus == SUCCESS)//启动成功
{
/*这两条FLASH指令必须加上，不知为啥？不加上就运行几秒后出错，参照系统初始化*/
/* Enable The Prefetch Buffer */
 FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);//FLASH缓存开启
 /* Configure the Latency cycle: Set 2 Latency cycles */
  FLASH_SetLatency(FLASH_Latency_2);  //设置FLASH这些位表示SYSCLK(系统时钟)周期与闪存访问时间的比例,为010：两个等待状态，当 48MHz < SYSCLK ≤ 72MHz
 /* Set PLL clock output to 72MHz using HSE (8MHz) as entry clock */
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);//外部时钟为8M，PLL的输入时钟=8MHZ，倍频系数9，

/* Configure HCLK such as HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);//设置了啦AHB分频器的分频系数=1，即HCLK=SYSCLK=72MHZ
/* Configure PCLK1 such as PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div2);//设置了APB1外设的时钟频率最大是36M这里是APB1的分频器设为2,PCLK1=HCLK/2=72/2=36MHZ正好是最大值
/* Configure PCLK2 such as PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);//设置PLCK2=HCLK=72MHZ，的APB2分频器=1
/* Select the PLL as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);//设置了SYSCLK的提供者为PLL，频率由上面算出=72MHZ
/* disable PLL Ready interrupt */
RCC_ITConfig(RCC_IT_PLLRDY, DISABLE);//PLL中断关闭
/* disable PLL Ready interrupt */
RCC_ITConfig(RCC_IT_HSERDY,DISABLE);//HSE中断关闭
/* disable PLL Ready interrupt */
RCC_ITConfig(RCC_IT_HSIRDY, DISABLE); //HSI中断关闭
/* disable PLL Ready interrupt */
RCC_ITConfig(RCC_IT_LSERDY, DISABLE); //LSE中断关闭
/* disable PLL Ready interrupt */
RCC_ITConfig(RCC_IT_LSIRDY, DISABLE); //LSI中断关闭

/* PLL clock divided by 1.5 used as USB clock source */
RCC_USBCLKConfig(RCC_USBCLKSource_PLLCLK_1Div5);//设置USB的时钟为=72、1.5=48mhz
/* Configure ADCCLK such as ADCCLK = PCLK2/2 */
RCC_ADCCLKConfig(RCC_PCLK2_Div2);//设置ADC时钟=PCLK2/2= 36MHZ
/* disable the LSE */
RCC_LSEConfig(RCC_LSE_OFF);//外部低速晶振关闭

/*DISable the RTC clock */
RCC_RTCCLKCmd(DISABLE);
/* DISable the Clock Security System */
RCC_ClockSecuritySystemCmd(DISABLE);
/* Enable the PLL */
RCC_PLLCmd(ENABLE);//使能PLL

 

 

 

/* PLL ans system clock config */
}
else
{
/* Add here some code to deal with this error */
}

 

 

}

/** @addtogroup STM32F10x_StdPeriph_Examples
  * @{
  */

/** @addtogroup SysTick_TimeBase
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
static __IO uint32_t TimingDelay;

/* Private function prototypes -----------------------------------------------*/
void Delay(__IO uint32_t nTime);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program.
  * @param  None
  * @retval None
  */


void wang_mySYStick_init()
{

//SysTick->LOAD=72000; //53MHZ下定时1ms
 SysTick->LOAD  = 72000;

 SysTick->CTRL=0x00000005;//表示HCLK=SYStick时钟，开启滴答，关闭中断


}

/*
*此函数为滴答时钟的查询函数，不断地在查询标志位！！！！
*
*  王均伟
*
* 形参为时间值，延时时间=TIME*1毫秒

*/
void mydelay(unsigned int time) //20110725他妈的我没找到关于这个版本的库函数，直接对寄存器操作了、反而感觉更亲切了。很想51
{
unsigned long a,b;
   while(time)
   {
     a=SysTick->CTRL;
  b=a&0x00010000;
   if(b==0x00010000)
   {
    SysTick->LOAD  = 72000-1;  //用的72MHZ时钟，一直使用的话要减一！！！！
  time--;
   }

 

   }

}
int main(void)
{ 

mysysint();//系统初始化程序

 /* GPIOD Periph clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);//使能时钟
/* Configure PD0 and PD2 in output pushpull mode */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9| GPIO_Pin_10| GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOD, &GPIO_InitStructure);


 wang_mySYStick_init();//滴答初始化！

  while(1)
  {
      /* Set the GPIOA port pin 10 and pin 15 */
  GPIO_SetBits(GPIOD,  GPIO_Pin_8);//GPIOD->BSRR = 0x00000f00;//置为PD8-PD11
 mydelay(100);

   /* Clears the GPIOA port pin 10 and pin 15 */
    GPIO_ResetBits(GPIOD,  GPIO_Pin_8);//GPIOD->BRR  = 0x00000f00;
 
mydelay(100);
  /* Set the GPIOA port pin 10 and pin 15 */
  GPIO_SetBits(GPIOD, GPIO_Pin_9);//GPIOD->BSRR = 0x00000f00;//置为PD8-PD11
 mydelay(100);

   /* Clears the GPIOA port pin 10 and pin 15 */
    GPIO_ResetBits(GPIOD,  GPIO_Pin_9);//GPIOD->BRR  = 0x00000f00;
 
 mydelay(100);
 
  /* Set the GPIOA port pin 10 and pin 15 */
  GPIO_SetBits(GPIOD, GPIO_Pin_10);//GPIOD->BSRR = 0x00000f00;//置为PD8-PD11
 mydelay(100);

   /* Clears the GPIOA port pin 10 and pin 15 */
    GPIO_ResetBits(GPIOD,  GPIO_Pin_10);//GPIOD->BRR  = 0x00000f00;
 
 
  mydelay(100);
  /* Set the GPIOA port pin 10 and pin 15 */
  GPIO_SetBits(GPIOD, GPIO_Pin_11);//GPIOD->BSRR = 0x00000f00;//置为PD8-PD11
 mydelay(100);

   /* Clears the GPIOA port pin 10 and pin 15 */
    GPIO_ResetBits(GPIOD,  GPIO_Pin_11);//GPIOD->BRR  = 0x00000f00;
 
 mydelay(100);
 
 
  }