main.c

stm32初级例程

/*----------------------------------------------------------------------------
本例子实现外部中断功能

 
例子使用PE2,PE2与KEY1相连，按下KEY1，就可以点亮LED灯了

 *---------------------------------------------------------------------------*/

/* Includes ------------------------------------------------------------------*/
#define SYS_GLOBALS
#include "include.h"

#define LED2_ON GPIO_ResetBits(GPIOC, GPIO_Pin_2)
#define LED2_OFF GPIO_SetBits(GPIOC, GPIO_Pin_2)

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void NVIC_Configuration(void);
void GPIO_Configuration(void);
void Exit_Configuration(void);
/* Private functions ---------------------------------------------------------*/

//中断函数
void EXTI15_10_IRQHandler(void)
{
  //判断中断管脚
  if(EXTI_GetITStatus(EXTI_Line12) != RESET)
  {
    /* Toggle PC8 pin */
    GPIO_WriteBit(GPIOC, GPIO_Pin_8, (BitAction)((1-GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_8))));

    /* Clear the EXTI line 12 pending bit */
	//清除中断标准
    EXTI_ClearITPendingBit(EXTI_Line12);
  }
}

/*******************************************************************************
* Function Name  : main
* Description    : Main program.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
int main(void)
{
#ifdef DEBUG
  debug();
#endif

  /* System Clocks Configuration */
  RCC_Configuration();//配置系统时钟   

  GPIO_Configuration();//配置GPIO
  

  /* NVIC configuration */
  NVIC_Configuration();//配置中断

  Exit_Configuration();

  //SysTick_Init();//系统定时器初始化
  //Timer2_Configuration();//定时器2初始化
  while(1);
  
}

void Exit_Configuration(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	EXTI_InitTypeDef EXTI_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	//外部中断使用的RCC时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE|RCC_APB2Periph_AFIO, ENABLE);//使能GPIO时钟  
	
	//外部中断使用的GPIO配置
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOE, &GPIO_InitStructure);  
	
	/* Connect EXTI Line2 to PE.2 */
	EXTI_ClearITPendingBit(EXTI_Line2);
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource2);
	
	/* Configure EXTI Line2 to generate an interrupt on falling edge */
	//配置外部中断  
	EXTI_InitStructure.EXTI_Line = EXTI_Line2;
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_Init(&EXTI_InitStructure);
	
	/* Generate software interrupt: simulate a falling edge applied on EXTI line 12 */
	//这里是软件模拟产生中断
//	EXTI_GenerateSWInterrupt(EXTI_Line2);
	
	if(EXTI_GetITStatus(EXTI_Line2) != RESET)
	{
		/* Clear the EXTI line 2 pending bit */
		EXTI_ClearITPendingBit(EXTI_Line2);
	}
	
	//外部中断使用的NVIC配置
	/* Configure one bit for preemption priority */
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
	
	/* Enable the EXTI15_10 Interrupt */
	NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQChannel;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
}

/*******************************************************************************
* Function Name  : RCC_Configuration
* Description    : Configures the different system clocks.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void RCC_Configuration(void)
{ErrorStatus HSEStartUpStatus;   
  
  /* RCC system reset(for debug purpose) */
  RCC_DeInit();

  /* Enable HSE */
  RCC_HSEConfig(RCC_HSE_ON);//使能外部时钟 

  /* Wait till HSE is ready */
  HSEStartUpStatus = RCC_WaitForHSEStartUp();//等待外部时钟就绪

  if(HSEStartUpStatus == SUCCESS)
  {
    /* Enable Prefetch Buffer 启用预取缓冲器 */
    FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

    /* Flash 2 wait state FLASH设置2个等待周期*/
    FLASH_SetLatency(FLASH_Latency_2);
 
    /* HCLK = SYSCLK 设置系统设置*/
    RCC_HCLKConfig(RCC_SYSCLK_Div1); 
  
    /* PCLK2 = HCLK PCLK2时钟=主时钟*/
    RCC_PCLK2Config(RCC_HCLK_Div1); 

    /* PCLK1 = HCLK/2 PCLK1时钟为主时钟1/2*/
    RCC_PCLK1Config(RCC_HCLK_Div2);

    /* PLLCLK = 8MHz * 9 = 72 MHz 设置时钟为72M*/
    RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

    /* Enable PLL 使能PLL*/ 
    RCC_PLLCmd(ENABLE);

    /* Wait till PLL is ready 等待PLL工作稳定*/
    while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
    {
    }

    /* Select PLL as system clock source 选择PLL做为系统时钟源*/
    RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

    /* Wait till PLL is used as system clock source 准备就绪，开始干活*/
    while(RCC_GetSYSCLKSource() != 0x08)
    {
    }
  }
}

/*******************************************************************************
* Function Name  : GPIO_Configuration
* Description    : Configures the different GPIO ports.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
  
  /* Enable GPIO_LED clock */
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC , ENABLE );

	/* Configure IO connected to LED0, LED1, LED2  *********************/	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2;
  	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
  	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  	GPIO_Init(GPIOC, &GPIO_InitStructure);
	 
}

/*******************************************************************************
* Function Name  : NVIC_Configuration
* Description    : Configures Vector Table base location.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void NVIC_Configuration(void)
{

//#ifdef  VECT_TAB_RAM
#if defined (VECT_TAB_RAM)
  /* Set the Vector Table base location at 0x20000000 */ 
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); //设置中断向量在RAM中
//#elif defined(VECT_TAB_FLASH_IAP)
//  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x2000);
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */ 
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); //设置中断向量在FLASH中  
#endif


}




#ifdef  DEBUG
/*******************************************************************************
* Function Name  : assert_failed
* Description    : Reports the name of the source file and the source line number
*                  where the assert_param error has occurred.
* Input          : - file: pointer to the source file name
*                  - line: assert_param error line source number
* Output         : None
* Return         : None
*******************************************************************************/
void assert_failed(u8* file, u32 line)
{ 
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif

/******************* (C) COPYRIGHT 2008 STMicroelectronics *****END OF FILE****/