STM32F PWM的生成

void TIME3_Config(void)
{
     TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 GPIO_InitTypeDef GPIO_InitStructure;
 TIM_OCInitTypeDef  TIM_OCInitStructure;
   //第一步：配置时钟
   // GPIOC Configuration: Channel 6 as alternate function push-pull
   RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
   //第二步，配置goio口
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
   GPIO_Init(GPIOC, &GPIO_InitStructure);
   GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_TIM3);
  
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //TIM2时钟使能

 TIM_TimeBaseStructure.TIM_Period =1000UL-1;  // 自动重装载寄存器周期的值 ;
 TIM_TimeBaseStructure.TIM_Prescaler = 30UL-1;  // 设置了用来作为TIM2时钟频率除数的预分频值。20S
 TIM_TimeBaseStructure.TIM_ClockDivision = 0; // 设置了时钟分割。
 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; // TIM向上计数模式 ;
 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

 //第四步pwm输出配置
        TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM2;               //设置为pwm2输出模式
   TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable;//正向通道有效
        TIM_OCInitStructure.TIM_Pulse=500;                                 //设置占空比时间
        TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;              //设置输出极性
        TIM_OC1Init(TIM3,&TIM_OCInitStructure);                      //按照指定参数初始化
  TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

//第五步，使能端的打开
  //TIM8计数器使能
  TIM_ARRPreloadConfig(TIM3,ENABLE);
  TIM_Cmd(TIM3,ENABLE);                            //打开TIM8 
}