pwm输出为什么有一段正常，一段不正常

笨鸟先飞鱼 · 发表于 2015-9-24 09:50:14

void TIM14_PWM_Init(void)
{
   //????·??è????????IO???è??

   GPIO_InitTypeDef GPIO_InitStructure;
   TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
   TIM_OCInitTypeDef TIM_OCInitStructure;

   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM14,ENABLE);     //TIM14?±??????
   RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);    //????PORTF?±??

   GPIO_PinAFConfig(GPIOF,GPIO_PinSource9,GPIO_AF_TIM14); //GPIOF9???????¨?±?÷14

   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;           //GPIOF9
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;        //????????
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;   //????100MHz
   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;      //???©????
   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;        //????
   GPIO_Init(GPIOF,&GPIO_InitStructure);              //??????PF9

   TIM_TimeBaseStructure.TIM_Prescaler=83; //?¨?±?÷·???
   TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;         //?ò??????????
   TIM_TimeBaseStructure.TIM_Period=99;    //×?????×°????
   TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;

   TIM_TimeBaseInit(TIM14,&TIM_TimeBaseStructure);            //???????¨?±?÷14


   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //?????¨?±?÷????:TIM?????í???÷??????2

   TIM_OCInitStructure.TIM_Pulse =50;   //?è??????±?
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;          //±???????????
   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;        //????????:TIM????±?????????
   TIM_OC1Init(TIM14, &TIM_OCInitStructure);    //?ù??T???¨???????????????èTIM1 4OC1

   TIM_OC1PreloadConfig(TIM14, TIM_OCPreload_Enable); //????TIM14??CCR1?????¤×°???????÷

TIM_ARRPreloadConfig(TIM14,ENABLE);         //ARPE????

   TIM_Cmd(TIM14, ENABLE); //????TIM14


}

初始化这个函数以后 STM32 F4007 板子，为什么pF9 输出的方波不正常，一会有，一会没有。除了10khz的波以外，就是规律的有一段时间是没有波形的，请问下为什么呢？