TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
        NVIC_InitTypeDef NVIC_InitStructure;
       
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14,ENABLE);  
       
  TIM_TimeBaseInitStructure.TIM_Period = arr;         //自动重装载值
        TIM_TimeBaseInitStructure.TIM_Prescaler=psc;  //定时器分频
        TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
        TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
       
        TIM_TimeBaseInit(TIM14,&TIM_TimeBaseInitStructure);
       
        TIM_ITConfig(TIM14,TIM_IT_Update,ENABLE);
        TIM_Cmd(TIM14,ENABLE);
       
        LCD_ShowString(30,210,200,16,16,"TIM_Cmd success");
       
        NVIC_InitStructure.NVIC_IRQChannel=TIM8_TRG_COM_TIM14_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x01; //抢占优先级1
        NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x03; //子优先级3
        NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       
        LCD_ShowString(30,210,200,16,16,"TIM14_init success");




这里两个lcd函数是为了观察函数运行到哪里了，在lcd上只显示了TIM_Cmd successs，然后就死在那里了。