如题,程序里有两个功能,一是定时器1输出两路PWM,单独仿真和下载进去没有问题,都有输出; 
二是通过定时器2周期性中断改变定时器1的脉宽,实现脉宽调节功能,加上这个功能后,仿真可以实现,下载后没输出 
什么原因呢? 
void tiM1_PWM_Init(u16 arr,u16 psc) 
{ 
GPIO_InitTypeDef GPIO_InitStructure; 
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure; 
TIM_OCInitTypeDef  TIM_OCInitStructure; 
// NVIC_InitTypeDef NVIC_InitStructure; 
RCC_APB2PeriphclockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE); //使能定时器3时钟 
 
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8|GPIO_Pin_9; //TIM_CH2 
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //复用推挽输出 
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIO 
GPIO_ResetBits(GPIOA,GPIO_Pin_8|GPIO_Pin_9); 
   //初始化TIM1 
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值 
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim 
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned3;  //TIM向上计数模式 
// TIM_TimeBaseStructure.TIM_RepetitionCounter = 10; 
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位 
 
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能 
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高 
TIM_OC1Init(TIM1, &TIM_OCInitStructure);  //根据T指定的参数初始化外设TIM3 OC2 
 
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2 
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能 
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高 
  TIM_OC2Init(TIM1, &TIM_OCInitStructure); 
 
// TIM_CleaRFlag(TIM1, TIM_FLAG_Update); //清中断,以免一启用中断后立即产生中断 
// TIM_CtrlPWMOutputs(TIM1,ENABLE); 
// TIM_Cmd(TIM1, ENABLE);  //使能TIM3 
 
} 
 
void TIM3_Int_Init(u16 arr,u16 psc) 
{ 
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure; 
NVIC_InitTypeDef NVIC_InitStructure; 
 
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //时钟使能 
 
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 计数到5000为500ms 
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值  10Khz的计数频率   
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim 
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式 
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位 
 
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //使能指定的TIM3中断,允许更新中断 
 
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  //TIM3中断 
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  //先占优先级0级 
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //从优先级3级 
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能 
NVIC_Init(&NVIC_InitStructure);  //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器 
 
TIM_Cmd(TIM3, ENABLE);  //使能TIMx外设 
 
} 
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