洛千叶 发表于 2017-6-14 16:00:14

STM32F103高级定时器输出PWM，波形滞后几秒

STM32高级定时器修改CCR寄存器的值过几秒后占空比才改变怎么回事?以下是初始化程序
/* PWM信号电平跳变值 */
TIM_TimeBaseInitTypeDefTIM_TimeBaseStructure;
TIM_OCInitTypeDefTIM_OCInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_TIM1 | RCC_APB2Periph_AFIO, ENABLE);

GPIO_InitStructure.GPIO_Pin =GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 20000-1;
TIM_TimeBaseStructure.TIM_Prescaler = 72-1; // 频率50Hz
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;           //比较输出使能
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;//选择互补输出比较状态

TIM_OCInitStructure.TIM_Pulse = 1000;                        //设置了待装入捕获比较器的脉冲值
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;        //设置输出极性
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;//开反向通道    设置互补输出极性
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;//选择空闲状态下得非工作状态
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;        //选择互补空闲状态下得非工作状态

TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

/* PWM1 Mode configuration: Channel2 */

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_Pulse = 1000;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;//开反向通道
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;          

TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);       

/* PWM1 Mode configuration: Channel3 */

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_Pulse = 1000;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;//开反向通道
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;          

TIM_OC3Init(TIM1, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable);       

//=========================================================
TIM_ARRPreloadConfig(TIM1, ENABLE);

/* TIM1 enable counter */
TIM_Cmd(TIM1, ENABLE);
TIM_CtrlPWMOutputs(TIM1, ENABLE);       

洛千叶 发表于 2017-6-14 16:18:03

问题解决了
TIM_TimeBaseStructure.TIM_RepetitionCounter=0x00;//周期数值
加上这一句就可以了
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