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/****************************************
**对定时器的库函数中各参数进行说明
**此次将在定时器输出PWM信号的同时,启用定时器中断服务。
**没啥特别的,只是可以在必要时节省定时器资源。
**注意:此方法的定时器中断周期与PWM输出周期相同
****************************************
**个人习惯:在初始化操作中使用库函数进行操作;
** 在对时间有要求的地方,建议使用操作寄存器,操作寄存器应采用 & | << 等运算符。
** 在处理乘除法操作时,若跟2有次方关系,可采用移位运算解决,减少处理时间,
** 这样操作不会出现浮点数,先考虑清楚是否需要浮点数。
****************************************/
//pfreq为分频值=系统工作频率/目标频率,
//psc为预分频值,当pfreq的值超过u16时,使用其将系统工作频率分频
void TIM1_PWM_Init(u16 pfreq ,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure; //管脚设置
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; //定时器基本寄存器设置
TIM_OCInitTypeDef TIM_OCInitStructure; //输出通道配置
TIM_BDTRInitTypeDef TIM_BDTRInitStructure; //死区和刹车配置
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB, ENABLE);
/* IO口管脚配置 */
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);
//互补通道
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* 定时器1配置 */
TIM_TimeBaseStructure.TIM_Period = pfreq;
TIM_TimeBaseStructure.TIM_Prescaler = psc;
//时钟分频设置
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
//计数方式:主要分为 向上、向下、中央计数三种,是有区别的。。。
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
//重复计数器的值 主要针对PWM信号。详见STM32参考手册
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
//初始化
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* PWM通道配置 */
//PWM模式 1:CNT小于CCR有效 2:CNT大于CCR有效
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
//设置主/互补输出使能
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
//设置输出PWM占空比 ,右移一位等同于除以2。
TIM_OCInitStructure.TIM_Pulse = pfreq >> 1;
//主/互补输出高电平有效
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCPolarity_High;
//设置主/互补空闲输出状态
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
//初始化定时器通道
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_OC3Init(TIM1, &TIM_OCInitStructure);
//使能定时器外围设备预加载器
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable);
/* 死区与互补通道配置 */
//运行模式下Off-State选择 = 1
TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
//空闲模式下Off-State选择 = 1
TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
//锁定级别为1
TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_1;
//死区时间
TIM_BDTRInitStructure.TIM_DeadTime = 0x04;
//关闭刹车输入
TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
//如开启刹车输入:刹车输入极性为低电平
TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
//禁止自动输出
TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Disable;
TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);
/* 定时器中断 */
TIM_ITConfig(TIM1,TIM_IT_Update,ENABLE );
//清除中断标志位
TIM_ClearFlag(TIM1, TIM_FLAG_Break);
//定时器1中断标识位在stm32f10x.h文件中定义
//定时器1的中断标识分一下四种,注:不同的版本的库函数其定义可能不同。
// TIM1_BRK_IRQn = 24, TIM1 Break Interrupt
// TIM1_UP_IRQn = 25, TIM1 Update Interrupt
// TIM1_TRG_COM_IRQn = 26, TIM1 Trigger and Commutation Interrupt
// TIM1_CC_IRQn = 27, TIM1 Capture Compare
NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQn;
//设置中断优先级、与中断通道使能
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 4;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
//使能定时器
TIM_Cmd(TIM1, ENABLE);
//使能外围设备输出,即使能PWM输出
TIM_CtrlPWMOutputs(TIM1,ENABLE);
}
//中断函数在启动文件中已经声明
//同理定时器1的中断服务函数也有很多
void TIM1_UP_IRQHandler(void)
{
if (TIM_GetITStatus(TIM1, TIM_IT_Update) != RESET)
{
/*
**具体指令
*/
TIM_ClearITPendingBit(TIM1, TIM_IT_Update);
}
}
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