STM32使用TIM1进行互补PWM输出时，示波器观察出两个波形

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june0929520 提问时间：2018-1-10 21:09 /

如题我使用的STM32F103RCT6，使用高级定时器TIM1进行PWM输出，PWM输出设置为周期设置100um，脉宽为50%。用示波器观察到两个波形，波形照片如下：

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上面这个波形的周期、脉宽和我设置的周期脉宽是一致的，但我将示波器时间调为1s,就出现如下的波形，这不是我想要的不知道为什么？

示波器时间为1S，就出现这样一个波形，这是为什么？这个波形周期为3S，脉宽也是50%。

如果我调整上面波形的占空比，下面的波形也会随着变化。可是我程序中就没有配置第二个这个波形，不知道从哪里来的。另外我将IO口上接上一个LED灯，灯也是一闪一闪的，并不是变暗。

各位大神，请问我这是什么情况？？？下面代码是我的配置代码。

void TIM1_Configuration(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 7200-1; //    10K
TIM_TimeBaseStructure.TIM_Prescaler =0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

/* Output Compare Active Mode configuration: Chan.ynel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable ;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
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_Set;
TIM_OCInitStructure.TIM_OCNIdleState =TIM_OCNIdleState_Reset;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_OC3Init(TIM1, &TIM_OCInitStructure);

  TIM_BDTRInitStructure.TIM_OSSIState=TIM_OSSIState_Enable;
  TIM_BDTRInitStructure.TIM_OSSRState=TIM_OSSRState_Enable;
  TIM_BDTRInitStructure.TIM_LOCKLevel=TIM_LOCKLevel_OFF;
  TIM_BDTRInitStructure.TIM_DeadTime=0Xab;
  TIM_BDTRInitStructure.TIM_Break=TIM_Break_Disable;
  TIM_BDTRInitStructure.TIM_BreakPolarity=TIM_BreakPolarity_Low;
  TIM_BDTRInitStructure.TIM_AutomaticOutput=TIM_AutomaticOutput_Disable;
  TIM_BDTRConfig(TIM1,&TIM_BDTRInitStructure);
  TIM_CtrlPWMOutputs(TIM1,ENABLE);
TIM_ARRPreloadConfig(TIM1, ENABLE);

/* TIM1 enable counter */
TIM_Cmd(TIM1, ENABLE);
}

//PWM输出使用的是如下代码：
TIM_SetCompare1(TIM1,3600);
TIM_SetCompare2(TIM1,3600);
TIM_SetCompare3(TIM1,3600);