你好原子哥，我想用外部中断触发定时器，当按键按下时定时器开始工作，实现15秒的倒计时，现在还没按按键定时器就开始工作，倒计时到0，也不能停止，用mini [mw_shl_code=c,true]void TIM3_Int_Init(u16 arr,u16 psc) { TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //时钟使能 TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 计数到5000为500ms TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值 10Khz的计数频率 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位 TIM_ClearFlag(TIM3, TIM_FLAG_Update); TIM_ITConfig( TIM3, TIM_IT_Update ,ENABLE); NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中断 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占优先级0级 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //从优先级3级 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能 NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器 TIM_Cmd(TIM3, ENABLE); //使能TIMx外设 } void TIM3_IRQHandler(void) //TIM3中断 { if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //检查指定的TIM中断发生与否:TIM 中断源 { LCD_ShowString(30,150,200,16,16," "); LCD_ShowNum(40,150,T1,2,16); LED1=!LED1; T1-=1; } TIM_ClearITPendingBit(TIM3, TIM_IT_Update ); //清除TIMx的中断待处理位:TIM 中断源 void EXTIX_Init(void) { EXTI_InitTypeDef EXTI_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);//外部中断，需要使能AFIO时钟 KEY_Init();//初始化按键对应io模式 //GPIOC.5 中断线以及中断初始化配置 GPIO_EXTILineConfig(GPIO_PortSourceGPIOC,GPIO_PinSource5); EXTI_InitStructure.EXTI_Line=EXTI_Line5; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;//下降沿触发 EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器 //GPIOA.15 中断线以及中断初始化配置 GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource15); EXTI_InitStructure.EXTI_Line=EXTI_Line15; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器 //GPIOA.0 中断线以及中断初始化配置 GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0); EXTI_InitStructure.EXTI_Line=EXTI_Line0; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); //根据EXTI_InitStruct中指定的参数初始化外设EXTI寄存器 NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; //使能按键所在的外部中断通道 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02; //抢占优先级2 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02; //子优先级1 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道 NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器 NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn; //使能按键所在的外部中断通道 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02; //抢占优先级2， NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01; //子优先级1 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道 NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn; //使能按键所在的外部中断通道 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02; //抢占优先级2， NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00; //子优先级1 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道 NVIC_Init(&NVIC_InitStructure); } void EXTI0_IRQHandler(void) { //delay_ms(10); //消抖 //if(WK_UP==0) NVIC_InitTypeDef NVIC_InitStructure; if ( EXTI_GetITStatus(EXTI_Line0) == RESET ) { EXTI_ClearITPendingBit(EXTI_Line0); GPIO_SetBits(GPIOA , GPIO_Pin_0); NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); //设置NVIC优先级分组 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //中断通道名 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;//抢占优先级 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //响应优先级 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //打开中断 NVIC_Init(&NVIC_InitStructure); //中断初始化 GPIO_ResetBits(GPIOA, GPIO_Pin_0); LED0=!LED0;} [/mw_shl_code]
板写的程序，您能帮我看看怎么回事吗