定时器时钟频率设置的通用写法。一般我们都是设置两个参数，分频系数和自动重装载值，
但是其实我们可以对其代码可以做进一步封装，直接频率作为参数传入，然后里面通过频率再计算分频系数和自动重装载值。
void TimerInit(u32 Frequency){ u32 Prescalar; u32 Period; if(Frequency>=16 && Frequency<500000) { Prescalar = 84; Period = SystemCoreClock/168/Frequency; } else if(Frequency<16) { Prescalar = 8400; Period = SystemCoreClock/168/100/Frequency; } else { Prescalar = 1; Period = SystemCoreClock/2/Frequency; } TIM_TimeBaseInitTypeDef TIM_TimeBaseInitTypeDefStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); TIM_DeInit(TIM3); TIM_TimeBaseInitTypeDefStructure.TIM_Period=(Period-1); TIM_TimeBaseInitTypeDefStructure.TIM_Prescaler=(Prescalar -1); TIM_TimeBaseInitTypeDefStructure.TIM_CounterMode=TIM_CounterMode_Up; TIM_TimeBaseInitTypeDefStructure.TIM_ClockDivision=TIM_CKD_DIV1; TIM_TimeBaseInit(TIM3,&TIM_TimeBaseInitTypeDefStructure); NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //外部中断8 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00; //抢占优先级1 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00; //子优先级2 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道 NVIC_Init(&NVIC_InitStructure); TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE); TIM_ClearITPendingBit(TIM3,TIM_IT_Update); TIM_Cmd(TIM3,DISABLE);}在输出PWM波形之前，首先需要找到哪些引脚可以复用为定时器，产生PWM波形，在原理图上其实特别好找。
u32 Prescalar;u32 Period;if(Frequency>=16 && Frequency<500000){ Prescalar = 168; Period = SystemCoreClock/168/Frequency;} else if(Frequency<16){ Prescalar = 16800; Period = SystemCoreClock/168/100/Frequency;}else{ Prescalar = 1; Period = SystemCoreClock/Frequency; } GPIO_InitTypeDef GPIO_InitStructure;TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;TIM_BDTRInitTypeDef TIM_BDTRStructure;TIM_OCInitTypeDef TIM_OCInitStructure;RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE); //TIM1时钟使能 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTA时钟 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); //使能PORTA时钟 GPIO_PinAFConfig(GPIOA,GPIO_PinSource8,GPIO_AF_TIM1); //GPIOA8复用为定时器1GPIO_PinAFConfig(GPIOA,GPIO_PinSource9,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOA,GPIO_PinSource10,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOA,GPIO_PinSource11,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOB,GPIO_PinSource13,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOB,GPIO_PinSource14,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOB,GPIO_PinSource15,GPIO_AF_TIM1);GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8|GPIO_Pin_9|GPIO_Pin_10|GPIO_Pin_11; //GPIOA8GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//速度100MHzGPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; //上拉GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA8GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//速度100MHzGPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; //上拉GPIO_Init(GPIOB,&GPIO_InitStructure); TIM_DeInit(TIM1); TIM_TimeBaseStructure.TIM_Prescaler=Prescalar-1; //定时器分频TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式TIM_TimeBaseStructure.TIM_Period=Period -1; //自动重装载值TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);//初始化定时器1//初始化TIM1 Channel1 PWM模式 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性低TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High ;//互补输出极性TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;//指定空闲状态下的TIM输出比较的引脚状态。TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;//指定空闲状态下的TIM互补输出比较的引脚状态。TIM_OCInitStructure.TIM_Pulse = Period /2; TIM_OC1Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 TIM_OC4Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设 TIM1 4OC1TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 TIM_OC2Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2TIM_OC3Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器 TIM_ARRPreloadConfig(TIM1,ENABLE);//ARPE使能TIM_CtrlPWMOutputs(TIM1,ENABLE); //输出使能，高级定时器特有的函数，通用定时器没有。TIM_Cmd(TIM1, ENABLE);//使能TIM1输出的波形如下：
如果需要使用PWM波形控制MOS管的开断，为防止同臂桥导通，就需要设置死区，正好高级定时器支持设置死区时间，笔者也整理成通用的代码，直接设置DeadTime即可设置死区时间，以ns为单位。
直接在上面的代码后面加上以下代码即可设置死区时间。
if(DeadTime<755) { SetTime=DeadTime/5.95; } else if(DeadTime>761&&DeadTime<1511) { SetTime=DeadTime/11.9-64+128; } else if(DeadTime>1511&&DeadTime<2973) { SetTime=DeadTime/47.2-32+192; } else if(DeadTime>3020&&DeadTime<5947) { SetTime=DeadTime/94.4-32+224; } TIM_BDTRStructure.TIM_AutomaticOutput=TIM_AutomaticOutput_Enable;// 自动输出功能使能??TIM_BDTRStructure.TIM_Break=TIM_Break_Disable; //失能刹车输入TIM_BDTRStructure.TIM_BreakPolarity=TIM_BreakPolarity_High; //刹车输入管脚极性高?TIM_BDTRStructure.TIM_DeadTime=SetTime; //输出打开和关闭状态之间的延时 TIM_BDTRStructure.TIM_LOCKLevel=TIM_LOCKLevel_OFF; // 锁电平参数: 不锁任何位TIM_BDTRStructure.TIM_OSSIState=TIM_OSSIState_Disable; //设置在空闲模式下非工作状态选项TIM_BDTRStructure.TIM_OSSRState=TIM_OSSRState_Disable; //设置在运行模式下非工作状态选项TIM_BDTRConfig(TIM1,&TIM_BDTRStructure);产生的互补波形如下，死区时间是：50ns
定时器里面提供一个函数，可以直接设置波形的个数，定时器结构体里面有个参数可以设置脉冲个数，即单脉冲模式。
TIM_TimeBaseStructure.TIM_RepetitionCounter=PulseNum;
TIM_SelectOnePulseMode(TIM1,TIM_OPMode_Single);
通过上面两个函数就可以生成特定个数得波形个数。下次如果需要再生成需要重新启动定时器。
//部分代码 TIM_TimeBaseStructure.TIM_Prescaler=Prescalar; //定时器分频TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式TIM_TimeBaseStructure.TIM_Period=Period-1; //自动重装载值TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; TIM_TimeBaseStructure.TIM_RepetitionCounter=PulseNum; //脉冲个数TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);//初始化定时器1TIM_SelectOnePulseMode(TIM1,TIM_OPMode_Single);特定个数的PMM波形。
很多时候，互补PWM波形作为Mos管的开关信号，需要在输出前为低电平。
但是STM32输出的PWM波形是互补的，必然两个波形中必然有一段时间是高电平的，即使在配置的时候，可以设置波形的极性和空闲状态，但是还是无用，无法设置成想要的波形。
下图为Mos管电路，需要PWM波形来控制。
在控制的时候，一般是设置固定的脉冲个数，所以还需要定时器在PWM波形输出完成之后，关闭定时器。
所以具体的设计思路就出来了：
1. STM32输出比较设置成单脉冲模型（特定个数），定时器1启动PWM之后，定时器2同时开始计时（利用定时器的波形个数来定时）。
2. 波形产生完毕之后，定时时间到，关闭定时器1，关闭定时器2，同时将IO模式变成普通模式，将电平拉低。
3. 同时如果要连续输出脉冲，所以需要定时器3做时间间隔定时。
u32 TIM1_PWM_Init(u32 Frequency,u16 DeadTime,u8 PulseNum){ //此部分需手动修改IO口设置u32 arr=0;u16 SetTime=0;GPIO_InitTypeDef GPIO_InitStructure;TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;TIM_BDTRInitTypeDef TIM_BDTRStructure;RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE); //TIM1时钟使能 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTA时钟 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); //使能PORTA时钟GPIO_PinAFConfig(GPIOA,GPIO_PinSource8,GPIO_AF_TIM1); //GPIOA8复用为定时器1GPIO_PinAFConfig(GPIOA,GPIO_PinSource11,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOB,GPIO_PinSource13,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOB,GPIO_PinSource14,GPIO_AF_TIM1);GPIO_PinAFConfig(GPIOB,GPIO_PinSource15,GPIO_AF_TIM1);GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8|GPIO_Pin_9|GPIO_Pin_10|GPIO_Pin_11; //GPIOA8GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//速度100MHzGPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; //上拉GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA8GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//速度100MHzGPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; //上拉GPIO_Init(GPIOB,&GPIO_InitStructure); TIM_DeInit(TIM1); arr=SystemCoreClock/Frequency; TIM_TimeBaseStructure.TIM_Prescaler=0; //定时器分频TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式TIM_TimeBaseStructure.TIM_Period=arr-1; //自动重装载值TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; TIM_TimeBaseStructure.TIM_RepetitionCounter=PulseNum;TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);//初始化定时器1TIM_SelectOnePulseMode(TIM1,TIM_OPMode_Single);//初始化TIM1 Channel1 PWM模式 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性低TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High ;//互补输出极性TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;//指定空闲状态下的TIM输出比较的引脚状态。TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;//指定空闲状态下的TIM互补输出比较的引脚状态。TIM_OCInitStructure.TIM_Pulse = arr/2; TIM_OC1Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 TIM_OC4Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2 TIM_OC2Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2TIM_OC3Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1 4OC1TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM1在CCR1上的预装载寄存器 if(DeadTime<755) { SetTime=DeadTime/5.95; } else if(DeadTime>761&&DeadTime<1511) { SetTime=DeadTime/11.9-64+128; } else if(DeadTime>1511&&DeadTime<2973) { SetTime=DeadTime/47.2-32+192; } else if(DeadTime>3020&&DeadTime<5947) { SetTime=DeadTime/94.4-32+224; } TIM_BDTRStructure.TIM_AutomaticOutput=TIM_AutomaticOutput_Enable;// 自动输出功能使能??TIM_BDTRStructure.TIM_Break=TIM_Break_Disable; //失能刹车输入TIM_BDTRStructure.TIM_BreakPolarity=TIM_BreakPolarity_High; //刹车输入管脚极性高?TIM_BDTRStructure.TIM_DeadTime=SetTime; //输出打开和关闭状态之间的延时 TIM_BDTRStructure.TIM_LOCKLevel=TIM_LOCKLevel_OFF; // 锁电平参数: 不锁任何位TIM_BDTRStructure.TIM_OSSIState=TIM_OSSIState_Disable; //设置在空闲模式下非工作状态选项TIM_BDTRStructure.TIM_OSSRState=TIM_OSSRState_Disable; //设置在运行模式下非工作状态选项TIM_BDTRConfig(TIM1,&TIM_BDTRStructure);TIM_ARRPreloadConfig(TIM1,ENABLE);//ARPE使能TIM_CtrlPWMOutputs(TIM1,ENABLE);TIM_Cmd(TIM1, DISABLE);//使能TIM1return arr; } void SetPulseNum(u8 PulseNum) //设置脉冲个数{ TIM1->RCR = PulseNum; TIM_GenerateEvent(TIM1,TIM_EventSource_Update);}void TIM3_IRQHandler(void){if(TIM_GetITStatus(TIM3,TIM_IT_Update)==SET) //溢出中断{ if(StartPWM_Flag) //开始产生PWM波形 { if(Count1==Tim3Count) //定时间隔产生PWM波形 { if(FirstEntryFlag!=0) //由于首次是复用模式，所以不用更改模式。 IOModeEnable(); TIM_Cmd(TIM1, ENABLE); //打开定时器1 TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); //允许定时器4更新中断 TIM_Cmd(TIM2,ENABLE); //打开定时器4 Count1=0; FirstEntryFlag=1; } else { Count1++; } }}TIM_ClearITPendingBit(TIM3,TIM_IT_Update); //清除中断标志位}void TIM2_IRQHandler(void){ //定时时间到if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET) //溢出中断{ TIM1->CR1 &= (uint16_t)~TIM_CR1_CEN; //关闭定时器1操作 IOModeDisable(); //IO模式 }TIM_ClearITPendingBit(TIM2,TIM_IT_Update); //清除中断标志位}产生的波形如下：
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