用STM32F051 TIM17产生两路带死区的互补pwm，互补pwm出来了，但死区没有，为什么？

我想用STM32F051 tiM17产生两路带死区的互补pwm，互补pwm出来了，但死区没有，不知道哪位大神有经验？

        TIM_TimeBaseStructure.TIM_Period = 4095;
        TIM_TimeBaseStructure.TIM_Prescaler = 11485;//11719;
        TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
        TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
        TIM_TimeBaseInit(TIM17,  TIM_TimeBaseStructure);
        TIM_ARRPreloadConfig(TIM17, ENABLE);

        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
        TIM_OCInitStructure.TIM_Pulse = 1000;
        TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
       TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
       TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
       TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
       TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Set;

        TIM_OC1Init(TIM17,  TIM_OCInitStructure);
        TIM_OC1PreloadConfig(TIM17, TIM_OCPreload_Enable);
        
        TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
        TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
        TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;
        TIM_BDTRInitStructure.TIM_DeadTime = 500;
        TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
       TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_Low;
       TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;
       TIM_BDTRConfig(TIM17,  TIM_BDTRInitStructure);
        
        TIM_ARRPreloadConfig(TIM17, ENABLE);
         
        TIM_Cmd(TIM17, ENABLE);
        TIM_CCPreloadControl(TIM17,ENABLE);
        TIM_CtrlPWMOutputs(TIM17, ENABLE);