自己的程序调了半天，读出来的数据一直为0。。。。。也是醉了，这是参考了官方例程的，能帮忙看看哪里不对吗？

[mw_shl_code=c,true]#include "stm32f4xx.h" #include "usart.h" #include "delay.h" #include "TIM2.h" volatile uint32_t x,y,a,b; int main(void) { uart_init(115200); delay_init(168); Tim2_Config(); while(1) { printf("%d %d ",a,b); delay_ms(1000); } } void Tim2_Config(void) { GPIO_InitTypeDef GPIO_InitStructure; TIM_ICInitTypeDef TIM_ICInitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure; DMA_InitTypeDef DMA_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA|RCC_AHB1Periph_DMA1,ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF; GPIO_InitStructure.GPIO_OType=GPIO_OType_PP ; GPIO_InitStructure.GPIO_Pin=GPIO_Pin_0 ; GPIO_InitStructure.GPIO_PuPd=GPIO_PuPd_UP ; GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz ; GPIO_Init(GPIOA,&GPIO_InitStructure); GPIO_PinAFConfig(GPIOA,GPIO_PinSource0,GPIO_AF_TIM2); NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn; NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1; NVIC_InitStructure.NVIC_IRQChannelSubPriority=1; NVIC_Init(&NVIC_InitStructure); TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1 ; TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up ; TIM_TimeBaseInitStructure.TIM_Period=0x00; TIM_TimeBaseInitStructure.TIM_Prescaler=0xa7; TIM_TimeBaseInitStructure.TIM_RepetitionCounter=0; TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure); TIM_ICInitStructure.TIM_Channel = TIM_Channel_1; TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising ; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM_ICInitStructure.TIM_ICFilter = 0x0; TIM_PWMIConfig(TIM2, &TIM_ICInitStructure); TIM_SelectInputTrigger(TIM2, TIM_TS_TI1FP1); TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset); TIM_SelectMasterSlaveMode(TIM2,TIM_MasterSlaveMode_Enable); TIM_Cmd(TIM2, ENABLE); TIM_ITConfig(TIM2,TIM_IT_CC1,ENABLE); } //中断函数 void TIM2_IRQHandler () { TIM_ClearITPendingBit(TIM2,TIM_IT_CC1); a=TIM_GetCapture1(TIM1); b=TIM_GetCapture1(TIM2); //a=b=10; } [/mw_shl_code]