STM8L 获取脉冲周期

只看该作者 · 2012-8-25 16:35

跪求高手指教..................
STM8L  获取脉冲周期
我把PD1设置为上升沿中断端口，来响应脉冲信号的上升沿，用TIM3计数，然后在中断处理函数里记录定时器计数值，为什么脉冲频率怎么变计数值差都在16、17之间徘徊
//TIM3初始化：
void TIM3_Init()
{
  TIM3_DeInit();
  TIM3_CounterModeConfig(TIM3_CounterMode_Up);
  TIM3_TimeBaseInit(TIM3_Prescaler_16, TIM3_CounterMode_Up, 32767);
  TIM3_PrescalerConfig(TIM3_Prescaler_16,  TIM3_PSCReloadMode_Immediate);
  TIM3_ARRPreloadConfig(ENABLE);          //ENABLE or DISABLE
  //TIM3_ITConfig(TIM2_IT_Update,ENABLE);
  TIM3_Cmd(ENABLE);
}

void EXTI_Init()
{

  EXTI_DeInit();
  EXTI_SelectPort(EXTI_Port_D);
  //EXTI_SetPortSensitivity(EXTI_Port_D,EXTI_Trigger_Falling);
  EXTI_SetPinSensitivity(EXTI_Pin_1, EXTI_Trigger_Rising);
  ITC_SetSoftwarePriority(EXTI1_IRQn, ITC_PriorityLevel_1);    //设置中断优先级
  GPIO_ExternalPullUpConfig(GPIOD, GPIO_Pin_1, ENABLE);
  GPIO_Init(GPIOD, GPIO_Pin_1, GPIO_Mode_In_FL_IT);
}

//中断处理函数
INTERRUPT_HANDLER(EXTI1_IRQHandler,9)
{
/* In order to detect unexpected events during development,
   it is recommended to set a breakpoint on the following instruction.
*/
  static int i = 0;
  //TIM3_Cmd(ENABLE);
  if(i!=10)
  {
m[i] = TIM3_GetCounter();
i++;
  }
  else
  {
GPIO_Init(GPIOD, GPIO_Pin_1, GPIO_Mode_In_FL_No_IT);
i = 0;
TIM3_Cmd(DISABLE);
  }
}