想看看在TIM1的重复计数器等于0的情况下，更新中断是在计数器上溢时发生，还是在下溢时发生 。就配置了下面的代码，在更新中断里面反转PD2引脚电平，与通道一输出的pwm波比较，用于指示更新中断产生的时刻，结果测量波形显示，在每一个计数周期中产生好几次更细中断，不知道这是为什么？？？求大神帮忙啊

1. int main(void)
   
2. {
   
3.     /* TIM Configuration */
   
4.   TIM_Config();
   
5. 
   
6.   /* Infinite loop */
   
7.   while (1)
   
8.   {
   
9.   }
   
10. }
    
11. 
    
12. /**
    
13.   * @brief  Configure the TIM1 Pins.
    
14.   * @param  None
    
15.   * @retval None
    
16.   */
    
17. static void TIM_Config(void)
    
18. {
    
19.   TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    
20.   TIM_OCInitTypeDef  TIM_OCInitStructure;
    
21.   GPIO_InitTypeDef GPIO_InitStructure;
    
22.   NVIC_InitTypeDef NVIC_InitStructure;
    
23.   /* GPIOA, GPIOB and GPIOE Clocks enable */
    
24.   RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOA | RCC_AHBPeriph_GPIOB|RCC_AHBPeriph_GPIOD, ENABLE);
    
25.   
    
26.   /* GPIOA Configuration: Channel 1, as alternate function push-pull */
    
27.   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 ;
    
28.   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    
29.   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    
30.   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    
31.   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
    
32.   GPIO_Init(GPIOA, &GPIO_InitStructure);
    
33.   
    
34.   GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_2);
    
35.    
    
36.          /*·´×ªÒý½Å*/
    
37.   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
    
38.   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
    
39.   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    
40.   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    
41.   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
    
42.   GPIO_Init(GPIOD, &GPIO_InitStructure);
    
43.   
    
44.   /* Compute the value to be set in ARR regiter to generate signal frequency at 17.57 Khz */
    
45.   TimerPeriod = (SystemCoreClock / 17570 ) - 1;
    
46.   /* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */
    
47.   Channel1Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10);
    
48. 
    
49.   /* TIM1 clock enable */
    
50.   RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE);
    
51.   
    
52.   /* Time Base configuration */
    
53.   TIM_TimeBaseStructure.TIM_Prescaler = 0;
    
54.   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned3;
    
55.   TIM_TimeBaseStructure.TIM_Period = TimerPeriod;
    
56.   TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    
57.   TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
    
58. 
    
59.   TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
    
60. 
    
61.   /* Channel 1, 2,3 and 4 Configuration in PWM mode */
    
62.   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
    
63.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
64.   TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    
65.   TIM_OCInitStructure.TIM_Pulse = Channel1Pulse;
    
66.   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    
67.   TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    
68.   TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
    
69.   TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
    
70. 
    
71.   TIM_OC1Init(TIM1, &TIM_OCInitStructure);
    
72. 
    
73.   TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE);
    
74.         
    
75.   /* TIM1 counter enable */
    
76.   TIM_Cmd(TIM1, ENABLE);
    
77. 
    
78.   /* TIM1 Main Output Enable */
    
79.   TIM_CtrlPWMOutputs(TIM1, ENABLE);
    
80.         
    
81.           /* Enable the TIM1 Trigger and commutation interrupt */
    
82.   NVIC_InitStructure.NVIC_IRQChannel = TIM1_BRK_UP_TRG_COM_IRQn;
    
83.   NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
    
84.   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    
85.   NVIC_Init(&NVIC_InitStructure);
    
86. }
    
87. 
    
88. 
    
89. 
    
90. 
    
91. 
    
92. 
    
93.   */
    
94. void TIM1_BRK_UP_TRG_COM_IRQHandler(void)
    
95. {
    
96.         if(TIM_GetITStatus(TIM1,TIM_IT_Update))
    
97.           {
    
98.                         GPIOD->ODR ^=GPIO_Pin_2;
    
99.     }
    
100. }
     

复制代码

自己已解决：问题出现在进入更新中断后，没有清除硬件中断标志，这样的话单片机内核以为一直有更行中断的产生，所以就会一直执行更新中断子程序，出现上述现象。在中断子函数中if语句内部加上一句：                        TIM_ClearITPendingBit(TIM1,TIM_IT_Update);，问题就解决了！

自己帮自己顶起，论坛里就没有高手遇到过这样的问题吗

帮顶

帮顶，。