编制测试TIM1定时100ms的精确时间程序

以下是一个简单的测试TIM1定时100ms的精确时间的程序示例，使用的是STM32F4 Discovery开发板：

#include "stm32f4xx.h"

volatile uint32_t start_time = 0;
volatile uint32_t end_time = 0;
volatile uint32_t elapsed_time = 0;

void TIM1_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM1, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM1, TIM_IT_Update);

        if (start_time == 0)
        {
            start_time = TIM_GetCapture1(TIM1);
        }
        else
        {
            end_time = TIM_GetCapture1(TIM1);
            elapsed_time = end_time - start_time;
            start_time = 0;
            end_time = 0;
        }
    }
}

int main(void)
{
    // Enable TIM1 clock
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    // Configure TIM1 as a timer with 100kHz frequency
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructure.TIM_Period = 999;
    TIM_TimeBaseStructure.TIM_Prescaler = 83;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

    // Enable TIM1 update interrupt
    TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE);

    // Enable TIM1 capture compare channel 1
    TIM_OCInitTypeDef TIM_OCInitStructure;
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
    TIM_OCInitStructure.TIM_Pulse = 0;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
    TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
    TIM_OC1Init(TIM1, &TIM_OCInitStructure);
    TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Disable);

    // Enable TIM1 counter
    TIM_Cmd(TIM1, ENABLE);

    // Enable TIM1 interrupt in NVIC
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_TIM10_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    while (1)
    {
        // Record start time
        start_time = TIM_GetCapture1(TIM1);

        // Run some code to be timed
        // ...

        // Record end time and calculate elapsed time
        end_time = TIM_GetCapture1(TIM1);
        elapsed_time = end_time - start_time;

        // Do something with elapsed time
        // ...
    }
}

在上面的代码中，我们配置了TIM1作为一个定时器，使用的预分频值为83，时钟源为84MHz，计数器的频率为100kHz。在TIM1的溢出中断服务函数中，记录了当前时间的值，并计算了两次中断之间的时间差，即为定时器精确时间的值。在主程序中，我们使用了两次定时器的捕获功能来记录开始时间和结束时间，并计算了它们的时间差。

请注意，上面的程序示例仅供参考，实际应用中可能需要根据具体的需求进行修改。