定时器如何重新开始计数

赤色忠心 · 发表于 2014-12-16 21:33:38

我写的程序思路为：当外部脉冲n来临时发生中断发生时，同时定时器开始定时，向上计数模式，中断时间为1秒，如果脉冲个数n+1在定时器发生中断前来临时，定时器重新开始定时，从0开始，当定时器中断发生时，外部中断n+1还没有来临，则清空n，使n=0,我使用的函数为TIM_SetAutoreload(TIM2,0);这样对吗?我写的程序如下
void TIM2_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //?±??????
TIM_ETRClockMode2Config(TIM2, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted, 0);

//?¨?±?÷TIM2??????
TIM_TimeBaseStructure.TIM_Period = arr; //?è???????????ü??????×°????????×?????×°???????÷????????
TIM_TimeBaseStructure.TIM_Prescaler =psc; //?è??????×÷??TIMx?±?????????????¤·?????
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //?è???±??·???:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM?ò???????
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //?ù?????¨????????????TIMx???±???ù??????

TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE ); //???????¨??TIM3????,???í?ü??????

NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn; //TIM3????
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3; //??????????0??
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //????????3??
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ?¨??±?????
NVIC_Init(&NVIC_InitStructure); //??????NVIC?????÷

TIM_Cmd(TIM2, ENABLE); //????TIMx
}
定时器服务函数
void TIM2_IRQHandler(void)
{
if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) //?ì?éTIM3?ü??????·??ú??·?
{
TIM_ClearITPendingBit(TIM2, TIM_IT_Update ); //????TIMx?ü??????±ê??
extinum=0;
extinum1=0;
extinum2=0;
extinum3=0;
}
}