使用STM32高级定时器（TIM8）PWM互补通道输出PWM

一、为何使用？

最近做项目，因为定时器不够用需要用高级定时器（TIM8）来输出PWM来控制电机，刚好硬件工程师把引脚分配到了TIM8定时器CH3的互补通道CH3_ON上。所以需要将CH3_ON当普通的PWM模式输出PWM，特意记录一下。

二、下面直接是高级定时器配置代码。

/*初始化IO脚*/
void ch3_oN_gpio_config(void)
{
    GPIO_InitTypeDef   GPIO_InitStructure;
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_AFIO,ENABLE);
	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //定时器需要复用推挽输出
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOB, &GPIO_InitStructure);
}

/*PWM配置*/
void ch3_oN_pwm_config(void)
{
    TIM_TimeBaseInitTypeDef		TIM_TimeBaseStructure;
	TIM_OCInitTypeDef			TIM_OCInitStructure;
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8, ENABLE);
	
	TIM_DeInit(TIM8);
	TIM_TimeBaseStructure.TIM_Prescaler = 0;//不分频
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//向上计数模式
	TIM_TimeBaseStructure.TIM_Period = 3599;
	TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
	TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0;
	TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
	
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;				//PWM模式2
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;	//关闭CH3通道
	TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;	//使能CH3_ON（互补）通道
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;				//空闲低电平
	TIM_OCInitStructure.TIM_OCNPolarity= TIM_OCNPolarity_Low;				//空闲低电平
	TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;			//死区后输出状态
	TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
	TIM_OCInitStructure.TIM_Pulse = 0;
		
	TIM_OC3Init(TIM8, &TIM_OCInitStructure); 			 //输出PWM
	TIM_OC3PreloadConfig(TIM8, TIM_OCPreload_Enable);
	TIM_OC3FastConfig(TIM8,TIM_OCFast_Enable);
	
	TIM_ARRPreloadConfig(TIM8,ENABLE);
	TIM_Cmd(TIM8, ENABLE);
	TIM_CtrlPWMOutputs(TIM8, ENABLE);//这一步一定要配置，主动打开高级定时器
	
	TIM_CCxCmd(TIM8,TIM_Channel_3,TIM_CCx_Disable);//关闭定时器8通道3
}

总结：使用高级定时器互补通道也能输出PWM。且不需要可以关闭正常通道，就是说高级定时器有7个通道可以输出PWM，其中CH4没有互补通道。