大家好！本人在调试TIM5-CH4;TIM8-CH2N两个通道产生PWM波的实验。但是TIM5-CH4可以输出正常，TIM3-CH3N的不行。下面是代码，希望大家看看，路过帮顶。是什么问题导致的呢？
KEIL5.14       stm32F205标准库开发  64引脚
void Time3_Time5_Configuration(void) //TIM3,TIM5ûÓÐÓõ½ÖжÏ
{
uint16_t PrescalerValue = 0;

GPIO_InitTypeDef    GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef     TIM_OCInitStructure;
  
// TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8, ENABLE); //TIM8 CH3N  
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE);     
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);


//TIM_InternalClockConfig(TIM5);
/* TIM8 CH2N */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14 ;  //motor2-EN  PB14
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;   
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_TIM8);
/* TIM5 CH3 */   
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;     //motor1-en  PA2
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;  
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_TIM5);


TIM_DeInit(TIM8);
TIM_DeInit(TIM5);
/* Time base configuration//133.333uS */
TIM_TimeBaseStructure.TIM_Period = 4000;  
TIM_TimeBaseStructure.TIM_Prescaler = 0;  //Ô¤·ÖƵÊýÎÞ
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //ʱÖÓ²»·ÖƵ
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //ÏòÉϼÆÊý
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure);


/* PWM1 Mode configuration:TIM3 Channel4 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;   //PWM1ΪÕý³£Õ¼¿Õ±Èģʽ¡£
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //ʹÄÜÊä³ö
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; //ʹÄÜÊä³ö

TIM_OCInitStructure.TIM_Pulse = 2000; //Õ¼¿Õ±ÈÉèÖÃ
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;

TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;

TIM_OC2Init(TIM8, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM8, TIM_OCPreload_Enable);  //CCR×Ô¶¯×°ÔعرÕ
TIM_ARRPreloadConfig(TIM8, ENABLE);//ARRÖØÔØʹÄÜ


  /* PWM1 Mode configuration:TIM5 Channel3 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;//PWM1ΪÕý³£Õ¼¿Õ±Èģʽ¡£
// TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 2000;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;

  TIM_OC3Init(TIM5, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM5, TIM_OCPreload_Enable);  //CCR×Ô¶¯×°ÔعرÕ
TIM_ARRPreloadConfig(TIM5, ENABLE);//ARRÖØÔØʹÄÜ

TIM_Cmd(TIM8, ENABLE);
TIM_CtrlPWMOutputs(TIM8, ENABLE);

TIM_Cmd(TIM5, ENABLE);
TIM_CtrlPWMOutputs(TIM5, ENABLE);

结果是TIM5有波形，Tim8的引脚上没有波形。不知道问题在哪里啊！搞了一天啦。哎

楼主你到底用的是TIM8还是TIM3呢？

可以自己用STM32CubeMX进行配置，参考STM32CubeMX的配置进行更改。