STM32F407 TIM11-CH1产生PWM波的问题

wbyrnygrysc

        TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
        GPIO_InitTypeDef GPIO_InitStructure;
        TIM_OCInitTypeDef TIM_OCInitStructure;

        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF,ENABLE);/*使能GPIOF时钟*/
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM11,ENABLE);/*使能定时器11时钟*/

        GPIO_PinAFConfig(GPIOF,GPIO_PinSource7,GPIO_AF_TIM11);/*复用*/

        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;/*复用*/
        GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;/*推挽输出*/
        GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_7;/*PF7*/
        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;/*上拉*/
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;/**/
        GPIO_Init(GPIOF,&GPIO_InitStructure);/*初始化IO*/

        TIM_TimeBaseInitStructure.TIM_Period = arr;/*自动重装载*/
        TIM_TimeBaseInitStructure.TIM_Prescaler = psc;/*预分频*/
        TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;/*时钟分频*/
        TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;/*向上计数*/
        TIM_TimeBaseInit(TIM11,&TIM_TimeBaseInitStructure);/*初始化*/

        TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;/*PWM模式*/
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;/*输出*/
        TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;/*起始是低*/
        TIM_OC1Init(TIM11,&TIM_OCInitStructure);

        TIM_OC1PreloadConfig(TIM11,TIM_OCPreload_Enable);/*输出比较预装载使能*/

        TIM_ARRPreloadConfig(TIM11,ENABLE);/*自动重载预装载使能*/

        TIM_Cmd(TIM11,ENABLE);/*计数使能*/


以上是初始化代码，初始化完成以后，用示波器测试发现波形不正常，

1208

检查下配置，或试下其它定时器通道正常不