为什么这么初始化在TIME1_CH2N和TIME1_CH3N引脚输不出PWM?有人在定时器的反向通道输出PWM吗？能帮我看看那有问题。

        GPIO_InitTypeDef GPIO_InitStructure;
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
        TIM_OCInitTypeDef  TIM_OCInitStructure;
        TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
       
        RCC_APB1PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);       
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO|RCC_APB2Periph_GPIOA , ENABLE);
        GPIO_PinRemapConfig(GPIO_PartialRemap_TIM1, ENABLE);
       
               
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8| GPIO_Pin_9;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //¸′óÃíÆíìêä3ö
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOA, &GPIO_InitStructure);//3õê¼»ˉGPIO
       
        TIM_TimeBaseStructure.TIM_Period = arr; //éèÖÃÔúÏÂò»¸ö¸üDÂê¼t×°èë»î¶ˉμÄ×Ô¶ˉÖØ×°ÔؼÄ′æÆ÷ÖüÆúμÄÖμ
        TIM_TimeBaseStructure.TIM_Prescaler =psc; //éèÖÃóÃà′×÷ÎaTIMxê±ÖóÆμÂê3yêyμÄÔ¤·ÖÆμÖμ
        TIM_TimeBaseStructure.TIM_ClockDivision = 0; //éèÖÃê±Öó·Ö¸î:TDTS = Tck_tim
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIMÏòéϼÆêyÄ￡ê½
        TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //¸ù¾YTIM_TimeBaseInitStructÖDÖ¸¶¨μÄ2Îêy3õê¼»ˉTIMxμÄê±¼ä»ùêyμ￥λ
       
        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //Ñ¡Ôñ¶¨ê±Æ÷Ä￡ê½:TIMÂö3å¿í¶èμ÷ÖÆÄ￡ê½2
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±è½Ïêä3öê1Äü
        TIM_OCInitStructure.TIM_OutputNState = TIM_OutputState_Enable; //±è½Ïêä3öê1Äü
        //TIM_OCInitStructure.TIM_Pulse=0;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCPolarity_High; //êä3ö¼«DÔ:TIMêä3ö±è½Ï¼«DÔ¸ß
        TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;       
  TIM_OC2Init(TIM1,&TIM_OCInitStructure);
       
        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //Ñ¡Ôñ¶¨ê±Æ÷Ä￡ê½:TIMÂö3å¿í¶èμ÷ÖÆÄ￡ê½2
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±è½Ïêä3öê1Äü
        TIM_OCInitStructure.TIM_OutputNState = TIM_OutputState_Enable; //±è½Ïêä3öê1Äü
        //TIM_OCInitStructure.TIM_Pulse=0;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCPolarity_High; //êä3ö¼«DÔ:TIMêä3ö±è½Ï¼«DÔ¸ß
        TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;       
  TIM_OC3Init(TIM1,&TIM_OCInitStructure);
       
        TIM_BDTRInitStructure.TIM_AutomaticOutput=TIM_AutomaticOutput_Enable;
        TIM_BDTRInitStructure.TIM_Break=TIM_Break_Disable;//TIM_Break_Enable;
        TIM_BDTRInitStructure.TIM_BreakPolarity=TIM_BreakPolarity_High;
        TIM_BDTRInitStructure.TIM_DeadTime=28;
        TIM_BDTRInitStructure.TIM_LOCKLevel=TIM_LOCKLevel_OFF;
        TIM_BDTRInitStructure.TIM_OSSIState=TIM_OSSIState_Disable;//TIM_OSSIState_Disable;//TIM_OSSIState_Enable;
        TIM_BDTRInitStructure.TIM_OSSRState=TIM_OSSRState_Disable;//TIM_OSSRState_Disable;//TIM_OSSRState_Enable;
        TIM_BDTRConfig(TIM1,&TIM_BDTRInitStructure);
       
        TIM_ARRPreloadConfig(TIM1,ENABLE);
        TIM_CtrlPWMOutputs(TIM1,ENABLE);//MOE=1,??OC?OCN??
        TIM_Cmd(TIM1,ENABLE);