stm32多路PWM

1

有点不是很清楚，怎么使能通道1和2的？
  TIM_OC1Init(TIM2, &TIM_OCInitStructure);         //使能通道1
  TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);

  /* PWM1 Mode configuration: Channel2 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = CCR2_Val;          //设置通道2的电平跳变值，输出另外一个占空比的PWM
  TIM_OC2Init(TIM2, &TIM_OCInitStructure);          //使能通道2