定时器无法进入中断

#include"stm32f4_discovery.h"

#include"stm32f4xx.h"



void led(int n);

void tim_config(void);

int flag=0;

void main()

{

  SystemInit();

  

  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12|GPIO_Pin_14;             

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT; /*端口模式为输出 */

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; /*输出类型 推挽输出 */

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_Init(GPIOD, &GPIO_InitStructure);

  tim_config();

}





void tim_config(void)

{

  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

  NVIC_InitTypeDef NVIC_InitStructure;

  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn; 

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占优先级为 0

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;    //响应优先级为 0

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;     //通道中断使能

  NVIC_Init(&NVIC_InitStructure);

  

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);

  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;

  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseStructure.TIM_Period = 9999;

  TIM_TimeBaseStructure.TIM_Prescaler = 7199;//定时1s



  TIM_TimeBaseInit(TIM2,&TIM_TimeBaseStructure);

  TIM_ClearFlag(TIM2,TIM_FLAG_Update);   

  TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);   

  TIM_Cmd(TIM2,ENABLE);

  

  

}



void led(int n)

{

    if(n==0){

      GPIO_SetBits(GPIOD,GPIO_Pin_12); 

      GPIO_SetBits(GPIOD,GPIO_Pin_14);

    }

    else if(n==1){

      GPIO_ResetBits(GPIOD,GPIO_Pin_12); 

      GPIO_ResetBits(GPIOD,GPIO_Pin_14);  

    

    }

}



void TIM2_IRQHandler(void)

{

  if(TIM_GetITStatus(TIM2,TIM_IT_Update)!=RESET)

  { 

    TIM_ClearFlag(TIM2,TIM_FLAG_Update);

    led(flag);

    flag=!flag;

  }

}



void Delay(uint32_t nCount)

{

 while (nCount--);

}





#ifdef  USE_FULL_ASSERT



/**

  * [url=home.php?mod=space&uid=247401]@brief[/url]  Reports the name of the source file and the source line number

  *         where the assert_param error has occurred.

  * @param  file: pointer to the source file name

  * @param  line: assert_param error line source number

  * @retval None

  */

void assert_failed(uint8_t* file, uint32_t 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) */



  while (1)

  {}

}

#endif



/**

  * @}

  */ 



/**

  * @}

  */ 



/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/