用c语言写一个stm32单片机定时20ms的程序

#include "stm32f10x.h"

void TIM2_IRQHandler(void) { if(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) { // 在此处添加要执行的代码 TIM_ClearITPendingBit(TIM2, TIM_IT_Update); } }

int main(void) { // 初始化时钟 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

// 初始化定时器
TIM_TimeBaseInitTypeDef TIM_InitStructure;
TIM_InitStructure.TIM_Period = 40000 - 1; // 计数器周期为20ms
TIM_InitStructure.TIM_Prescaler = 7200 - 1; // 预分频系数为7200，时钟频率为72MHz / 7200 = 10kHz
TIM_InitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_InitStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_InitStructure);

// 使能定时器中断
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

// 启动定时器
TIM_Cmd(TIM2, ENABLE);

while(1)
{
    // 程序主循环
}

}