程序到        NVIC_Init(&NVIC_InitStructure);这个位置就卡死了

        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM6, ENABLE);
        TIM_TimeBaseStructure.TIM_Period = 9;
        TIM_TimeBaseStructure.TIM_Prescaler =8399;
        TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
        TIM_TimeBaseInit(TIM6, &TIM_TimeBaseStructure);
       
        TIM_ITConfig(TIM6,TIM_IT_Update,ENABLE );
       
        NVIC_InitStructure.NVIC_IRQChannel = TIM6_DAC_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =1;
        NVIC_InitStructure.NVIC_IRQChannelSubPriority =0;
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
        NVIC_Init(&NVIC_InitStructure);
       TIM_Cmd(TIM6, ENABLE);
程序到        NVIC_Init(&NVIC_InitStructure);这个位置就卡死了