Question

想用stm32的TIM3的通道3做PWM输出，通道4做捕获输入，但是不知道怎么使用，请高手指教！

Answer 1

....前面省略了
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

/* 通道1工作模式 */
TIM_OCStructInit(&TIM_OCInitStructure); //其它默认值
//110：PWM模式1－ 在向上计数时，一旦TIMx_CNT<TIMx_CCR1时通道1为有效电平，否则为无效电平；
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //TIM_OCPolarity_Low;//输出极性0：高电平有效
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;//输出
TIM_OCInitStructure.TIM_Pulse = 50*(SYSTEM_CLOCK/1000000); //50us高电平
//1通道pwm
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3FastConfig(TIM3, TIM_OCFast_Enable);
TIM_OC3PreloadConfig(TIM3,TIM_OCPreload_Enable); //通道预装载使能
/* //12模拟输入捕获上升下降沿*/
TIM_ICInitStructure.TIM_Channel = TIM_Channel_4;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//TIM_ICSelection_IndirectTI;//
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0x08;
TIM_ICInit(TIM3, &TIM_ICInitStructure); TIM_ClearFlag(TIM3,TIM_FLAG_Update|TIM_FLAG_CC1|TIM_FLAG_CC2|TIM_FLAG_CC3|TIM_FLAG_CC4);
TIM_ITConfig(TIM3,TIM_IT_Update|TIM_IT_CC4, ENABLE);
TIM_Cmd(TIM3, ENABLE);

再加中断配置,不保证一定行大概意思就是这样了

Answer 2

就是配置寄存器嘛，根据参考手册来，上面怎么说就怎么配。