在自己小板子上移植PWM时候又重新学习了一下，加入两点：1，对各种输出比较模式的学习；2，输出模式时加入中断
先写出函数：
1 //TIM4 PWM部分初始化 2 //PWM输出初始化 3 //period：输出周期：KHz 4 //duty：占空比 0-100 5 //mode: 是否开启Tim4中断溢出中断与CC4中断 6 7 8 void TIM4_CH4_PB9_PWM_Init(unsigned short int period,char duty,char mode) 9 { 10 11 GPIO_InitTypeDef GPIO_InitStructure; 12 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; 13 TIM_OCInitTypeDef TIM_OCInitStructure; 14 NVIC_InitTypeDef NVIC_InitStructure; 15 16 17 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); //使能定时器4时钟 18 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外设和AFIO复用功能模块时钟 19 20 21 //设置该引脚为复用输出功能,输出TIM4 CH4的PWM脉冲波形 GPIOB.9 22 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //TIM_CH4 23 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出 24 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 25 GPIO_Init(GPIOB, &GPIO_InitStructure);//初始化GPIO 26 27 //初始化TIM4 28 TIM_TimeBaseStructure.TIM_Period = (1000/period); //设置在下一个更新事件装入活动的自动重装载寄存器周期的值,本身频率为1MHz，又分频器设置的下面一行 29 TIM_TimeBaseStructure.TIM_Prescaler =(72-1); //设置用来作为TIMx时钟频率除数的预分频值，72MHz/72=1MHz 30 TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim 31 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式 32 TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位 33 34 //初始化TIM4 Channel4 PWM模式 35 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2 36 TIM_OCInitStructure.TIM_Pulse=(10*duty/period); //(TIM_Period)*(duty/100) --> (1000/period)*(duty/100) 37 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能 38 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高 39 TIM_OC4Init(TIM4, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM4 OC4 40 41 TIM_OC4PreloadConfig(TIM4, TIM_OCPreload_Enable); //使能TIM4在CCR4上的预装载寄存器 42 TIM_Cmd(TIM4, ENABLE); //使能TIM4 43 44 if(mode) 45 { 46 /* Clear TIM4 update pending flag[清除TIM4溢出中断标志] */ 47 TIM_ClearITPendingBit(TIM4, TIM_IT_CC4 | TIM_IT_Update ); 48 /* TIM IT enable */ //打开溢出中断 49 TIM_ITConfig(TIM4, TIM_IT_CC4 | TIM_IT_Update, ENABLE); 50 51 /* Enable the TIM4 gloabal Interrupt */ 52 NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn; 53 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; 54 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; 55 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 56 NVIC_Init(&NVIC_InitStructure); 57 58 } 59 60 }