这个是STM32的PWM输出模式，STM32的TIM1模块是增强型的定时器模块，天生就是为电机控制而生，可以产生3组6路PWM，同时每组2路PWM为互补，并可以带有死区，可以用来驱动H桥。

　　下面的代码，是利用TIM1模块的1、2通道产生一共4路PWM的代码例子，类似代码也可以参考ST的固件库中相应example

C语言: TIM1模块产生PWM，带死区
     
//Step1.开启TIM和相应端口时钟
//启动GPIO
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | \
                       RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD,\
                       ENABLE);
//启动AFIO
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
//启动TIM1
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
//Step2. GPIO做相应设置，为AF输出
//PA.8/9口设置为TIM1的OC1输出口
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//PB.13/14口设置为TIM1_CH1N和TIM1_CH2N输出口
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
//Step3. TIM模块初始化
void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_BaseInitStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;
    TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
    //TIM1基本计数器设置（设置PWM频率）
    //频率=TIM1_CLK/(ARR+1)
    TIM_BaseInitStructure.TIM_Period = 1000-1;
    TIM_BaseInitStructure.TIM_Prescaler = 72-1;
    TIM_BaseInitStructure.TIM_ClockDivision = 0;
    TIM_BaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_BaseInitStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM1, &TIM_BaseInitStructure);
    //启用ARR的影子寄存器（直到产生更新事件才更改设置）
    TIM_ARRPreloadConfig(TIM1, ENABLE);
    //TIM1_OC1模块设置（设置1通道占空比）
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
    TIM_OCInitStructure.TIM_Pulse = 120;
    TIM_OC1Init(TIM1, &TIM_OCInitStructure);
    //启用CCR1寄存器的影子寄存器（直到产生更新事件才更改设置）
    TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
    //TIM2_OC2模块设置（设置2通道占空比）
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 680;
    TIM_OC2Init(TIM1, &TIM_OCInitStructure);
    //启用CCR2寄存器的影子寄存器（直到产生更新事件才更改设置）
    TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
   
    //死区设置
    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 = 0x90; //这里调整死区大小0-0xff
    TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
    TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
    TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;
    TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);
   
    //TIM1开启
    TIM_Cmd(TIM1, ENABLE);
    //TIM1_OC通道输出PWM（一定要加）
    TIM_CtrlPWMOutputs(TIM1, ENABLE);
}
  
　　其实，PWM模块还可以有很多花样可以玩，比方在异常时（如CPU时钟有问题），可以紧急关闭输出，以免发生电路烧毁等严重事故