stm32f051的TIM1的更新中断不正确的问题？？？

你好我好大家好！提问时间：2015-8-3 10:56 /

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

int main(void)
{
/* TIM Configuration */
TIM_Config();
/* Infinite loop */
while (1)
{
}
}
/**
* @brief Configure the TIM1 Pins.
* @param None
* @retval None
*/
static void TIM_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
/* GPIOA, GPIOB and GPIOE Clocks enable */
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOA | RCC_AHBPeriph_GPIOB|RCC_AHBPeriph_GPIOD, ENABLE);
/* GPIOA Configuration: Channel 1, as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_2);
/*·´×ªÒý½Å*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/* Compute the value to be set in ARR regiter to generate signal frequency at 17.57 Khz */
TimerPeriod = (SystemCoreClock / 17570 ) - 1;
/* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */
Channel1Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10);
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE);
/* Time Base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned3;
TIM_TimeBaseStructure.TIM_Period = TimerPeriod;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* Channel 1, 2,3 and 4 Configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_Pulse = Channel1Pulse;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE);
/* TIM1 counter enable */
TIM_Cmd(TIM1, ENABLE);
/* TIM1 Main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
/* Enable the TIM1 Trigger and commutation interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM1_BRK_UP_TRG_COM_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
*/
void TIM1_BRK_UP_TRG_COM_IRQHandler(void)
{
if(TIM_GetITStatus(TIM1,TIM_IT_Update))
{
GPIOD->ODR ^=GPIO_Pin_2;
}
}