STM32F103 在使能TIM4PWM输出后，delay_ms延时出错

恬静的守护 · 发表于 2017-9-5 17:16:32

   求教！    在将PD12重映射为TIM4 CH1并进行使能输出PWM波后，系统的delay_ms函数的延时出错，请问是什么原因？

   void TIM4_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); //使能TIMx外设
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD|RCC_APB2Periph_AFIO, ENABLE);  //使能GPIOB外设时钟使能

//设置该引脚为复用输出功能,输出TIM4 CH1的PWM脉冲波形
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12; //TIM_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //复用功能输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure); //初始化GPIO
GPIO_PinRemapConfig(GPIO_Remap_TIM4,ENABLE);

TIM_TimeBaseStructure.TIM_Period = arr; //设置自动重装载周期值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置预分频值不分频
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned1;  //TIM向上计数模式
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //CH1 PWM2模式
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_Pulse = 0; //设置待装入捕获比较寄存器的脉冲值
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //OC1 低电平有效
TIM_OC1Init(TIM4, &TIM_OCInitStructure);  //根据指定的参数初始化外设TIMx

TIM_OC1PreloadConfig(TIM4, TIM_OCPreload_Enable);  //CH1 预装载使能

TIM_ARRPreloadConfig(TIM4, ENABLE); //使能TIMx在ARR上的预装载寄存器

TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE);//使能更新触发TIM中断

//中断分组设置
NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;  //TIM4中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;  //先占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //从优先级3级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure);  //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器

TIM4->CCR1 = 36000;
   TIM_Cmd(TIM4, ENABLE);
}