stm32 tim1学习笔记

https://www.360docs.net/doc/8016779250.html,/BLOG_ARTICLE_187975.HTM

STM32笔记(一)TIM模块定时器向上溢出 & 输出比较 [ARM] 发布时间:2008-12-13 10:25:02
首先我们必须肯定ST公司的实力,也承认STM32的确是一款非常不错的Cortex-M3核单片机,但是,他的手册实在是让人觉得无法理解,尤其是其中
的TIM模块,没有条理可言,看了两天几乎还是不知所云,让人很是郁闷。同时配套的固件库的说明也很难和手册上的寄存器对应起来,研究起来非常费劲!功能
强大倒是真的,但至少也应该配套一个让人看的明白的说明吧~~


两天时间研究了STM32定时器的最最基础的部分,把定时器最基础的两个功能实现了,余下的功能有待继续学习。

首先有一点需要注意:FWLib固件库目前的最新版应该是V2.0.x,V1.0.x版本固件库中,TIM1模块被独立出来,调用的函数与其他定时器不同;在V2.0系列版本中,取消了TIM1.h,所有的TIM模块统一调用TIM.h即可。网络上流传的各种代码有许多是基于v1版本的固件库,在移植到v2版本固件库时,需要做些修改。本文的所有程序都是基于V2.0固件库。




以下是定时器向上溢出示例代码:





C语言: TIM1模块产生向上溢出事件


//Step1.时钟设置:启动TIM1


RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);



//Step2.中断NVIC设置:允许中断,设置优先级


NVIC_InitStructure.NVIC_IRQChannel =
TIM1_UP_IRQChannel;
//更新事件

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
//抢占优先级0

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
//响应优先级1

NVIC_InitStructure.NVIC_IRQChannelCmd =
ENABLE;
//允许中断

NVIC_Init(&NVIC_InitStructure);
//写入设置



//Step3.TIM1模块设置


void
TIM_Configuration(void)

{

TIM_TimeBaseInitTypeDef TIM_BaseInitStructure;

TIM_OCInitTypeDef TIM_OCInitStructure;





//TIM1
使用内部时钟

//TIM_InternalClockConfig(TIM1);




//TIM1基本设置


//设置预分频器分频系数71,即APB2=72M,
TIM1_CLK=72/72=1MHz

//TIM_Period(TIM1_ARR)=1000,计数器向上计数到1000后产生更新事件,计数值归零


//向上计数模式

//TIM_RepetitionCounter(TIM1_RCR)=0,每次向上溢出都产生更新事件


TIM_BaseInitStructure.TIM_Period = 1000;

TIM_BaseInitStructure.TIM_Prescaler = 71;

TIM_BaseInitStructure.TIM_ClockDivision = 0;

TIM_BaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_BaseInitStructure.TIM_RepetitionCounter = 0;

TIM_TimeBaseInit(TIM1,
&TIM_BaseInitStructure);



//清中断,以免一启用中断后立即产生中断


TIM_ClearFlag(TIM1, TIM_FLAG_Update);

//使能TIM1中断源


TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE);



//TIM1总开关

:开启


TIM_Cmd(TIM1, ENABLE);

}



//Step4.中断服务子程序:


void
TIM1_UP_IRQHandler(void)

{

GPIOC->ODR ^= (1<<4);
//闪灯

TIM_ClearITPendingBit(TIM1, TIM_FLAG_Update); //清中断

}






下面是输出比较功能实现TIM1_CH1管脚输出指定频率的脉冲:





C语言: TIM1模块实现输出比较,自动翻转并触发中断


//Step1.启动TIM1,同时还要注意给相应功能管脚启动时钟


RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);



//Step2.
PA.8口设置为TIM1的OC1输出口


GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);



//Step3.使能TIM1的输出比较匹配中断


NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQChannel;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);



//Step4.
TIM模块设置


void
TIM_Configuration(void)

{


TIM_TimeBaseInitTypeDef TIM_BaseInitStructure;


TIM_OCInitTypeDef TIM_OCInitStructure;





//TIM1基本计数器设置



TIM_BaseInitStructure.TIM_Period = 0xffff;
//这里必须是65535



TIM_BaseInitStructure.TIM_Prescaler = 71;
//预分频71,即72分频,得1M



TIM_BaseInitStructure.TIM_ClockDivision = 0;


TIM_BaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;


TIM_BaseInitStructure.TIM_RepetitionCounter = 0;


TIM_TimeBaseInit(TIM1,
&TIM_BaseInitStructure);



//TIM1_OC1模块设置



TIM_OCStructInit(&
TIM_OCInitStructure);


TIM_OCInitStructure.TIM_OCMode =
TIM_OCMode_Toggle;
//管脚输出模式:翻转



TIM_OCInitStructure.TIM_Pulse = 2000;
//翻转周期:2000个脉冲



TIM_OCInitStructure.TIM_OutputState =
TIM_OutputState_Enable;
//使能TIM1_CH1通道



TIM_OCInitStructure.TIM_OCPolarity =
TIM_OCPolarity_High;
//输出为正逻辑


TIM_OC1Init(TIM1,
&TIM_OCInitStructure);
//写入配置



//清中断


TIM_ClearFlag(TIM1, TIM_FLAG_CC1);



//TIM1中断源设置,开启相应通道的捕捉比较中断



TIM_ITConfig(TIM1, TIM_IT_CC1, ENABLE);



//TIM1开启


TIM_Cmd(TIM1, ENABLE);

//通道输出使能


TIM_CtrlPWMOutputs(TIM1, ENABLE);

}



Step5.中断服务子程序


void
TIM1_CC_IRQHandler(void)

{

u16
capture;

if(TIM_GetITStatus(TIM1,
TIM_IT_CC1) == SET)

{


TIM_ClearITPendingBit(TIM1, TIM_IT_CC1 );


capture = TIM_GetCapture1(TIM

1);


TIM_SetCompare1(TIM1, capture + 2000);


//这里解释下:


//将TIM1_CCR1的值增加2000,使得下一个TIM事件也需要2000个脉冲,



//另一种方式是清零脉冲计数器



//TIM_SetCounter(TIM2,0x0000);


}

}



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