问题代码

void TIM5_PWM_Init(u16 arr,u16 psc){//无端口重映射
	
	GPIO_InitTypeDef GPIO_InitTypeStructure;
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitTypeStructure;
	TIM_OCInitTypeDef TIM_OCInitTypeStructure;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE);//使能定时器3时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFIO,ENABLE);//使能AFIO和C的时钟
	
	//GPIO_PinRemapConfig(GPIO_Remap_TIM4,ENABLE);
	
	GPIO_InitTypeStructure.GPIO_Mode = GPIO_Mode_AF_PP;//初始化为推挽输出
	GPIO_InitTypeStructure.GPIO_Pin = GPIO_Pin_1;
	GPIO_InitTypeStructure.GPIO_Speed  = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA,&GPIO_InitTypeStructure);
	
	
	
	
	TIM_TimeBaseInitTypeStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitTypeStructure.TIM_Period = arr;
	TIM_TimeBaseInitTypeStructure.TIM_Prescaler = psc ;
	TIM_TimeBaseInitTypeStructure.TIM_ClockDivision = 0;
	TIM_TimeBaseInit(TIM5,&TIM_TimeBaseInitTypeStructure);
	
	
	TIM_OCInitTypeStructure.TIM_OCMode = TIM_OCMode_PWM2;
	TIM_OCInitTypeStructure.TIM_OCPolarity = TIM_OCPolarity_High;
	TIM_OCInitTypeStructure.TIM_OutputState = TIM_OutputState_Enable;
	TIM_OC2Init(TIM5,&TIM_OCInitTypeStructure);
	
	TIM_OC2PreloadConfig(TIM5,TIM_OCPreload_Enable);
	
	TIM_Cmd(TIM5,ENABLE);
}仅将TIM4改为TIM5就可以用了，TIM4无法输出PWM波