请教PWM产生固定频率方波的问题

只看该作者 · 2012-8-5 16:08

我想分别用TIM1　CH3和TIM4　CH2输出125KHz方波，TIM1的不知怎么写，TIM4的写了下，但没有输出，请指点下！
TIM4的初始化程序如下：
/**************************TIM4***************************************/
TIM_TimeBaseStructure.TIM_Prescaler = 35;       //时钟36分频，1us一个计数
TIM_TimeBaseStructure.TIM_ClockDivision = 0;    //时钟分割
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//模式
TIM_TimeBaseStructure.TIM_Period = 7;          //8us
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //基本初始化
/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 4;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC2Init(TIM4, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM4, ENABLE);
/* TIM4 enable counter */
TIM_Cmd(TIM4, ENABLE);

只看该作者 · 2012-8-5 16:31

搞定了TIM4，不好意思，我用的是重映射引脚，加上如下这句就可以了
GPIO_PinRemapConfig(GPIO_Remap_TIM4,ENABLE);
还差TIM1的了。

只看该作者 · 2012-8-5 21:05

看看，学习下

只看该作者 · 2012-8-6 10:06

这是我TIM1的初始化部分：也用的是重映射，用PE13引脚
TIM1_TimeBaseInitStruct.TIM1_Prescaler = 35; // 1us resolution
TIM1_TimeBaseInitStruct.TIM1_CounterMode = TIM1_CounterMode_Up;
TIM1_TimeBaseInitStruct.TIM1_Period = 7; // 8us->125K
TIM1_TimeBaseInitStruct.TIM1_ClockDivision = 0;
TIM1_TimeBaseInitStruct.TIM1_RepetitionCounter = 0;
TIM1_TimeBaseInit(&TIM1_TimeBaseInitStruct);

TIM1_OCInitStructure.TIM1_OCMode = TIM1_OCMode_PWM1;
TIM1_OCInitStructure.TIM1_OutputState = TIM1_OutputState_Enable;
TIM1_OCInitStructure.TIM1_OutputNState = TIM1_OutputNState_Disable;
TIM1_OCInitStructure.TIM1_Pulse = 4;
TIM1_OCInitStructure.TIM1_OCPolarity = TIM1_OCPolarity_High;
TIM1_OCInitStructure.TIM1_OCNPolarity = TIM1_OCNPolarity_Low;
TIM1_OCInitStructure.TIM1_OCIdleState = TIM1_OCIdleState_Set;
TIM1_OCInitStructure.TIM1_OCNIdleState = TIM1_OCIdleState_Reset;

TIM1_OC3Init(&TIM1_OCInitStructure);
TIM1_OC3PreloadConfig(TIM1_OCPreload_Enable);
TIM1_ARRPreloadConfig(ENABLE);
TIM1_Cmd(ENABLE);
但是不好用，还没有波形出现。请指点！