STM32定时器溢出模式设置

STM32定时器溢出模式设置

本文博客链接:http://blog.csdn.net/jdh99,作者:jdh,转载请注明.

环境：

主机:WIN7

开发环境:MDK4.23

MCU:STM32F103CBT6

源代码1:

说明:定时器采用TIM2,时钟源为内部8M晶振,向上溢出模式.此定时器用在延时函数,最小可以延时1us,故没有采用中断形式定时.

初始化代码:

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RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);

//重新将Timer设置为缺省值

TIM_DeInit(TIM2);

//采用内部时钟给TIM2提供时钟源

TIM_InternalClockConfig(TIM2);



timInitStruct.TIM_ClockDivision = TIM_CKD_DIV2; //定时器基准频率8MHz

timInitStruct.TIM_Prescaler = 8 - 1; //计数频率为1us跳转1次

timInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //向上计数

timInitStruct.TIM_RepetitionCounter = 0;

timInitStruct.TIM_Period = 0; //这个值实际上就是TIMX->ARR，延时开始时重新设定即可



TIM_TimeBaseInit(TIM2, &timInitStruct);

TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE); //计数溢出时触发中断

TIM_Cmd(TIM2, ENABLE); //开启计数器

延时函数代码:

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//延时1us

//最大65536us

void _delay_us(uint16_t t)

{

TIM_SetCounter(TIM2,0);

TIM_SetAutoreload(TIM2,t - 1);

//等待时间到

while (TIM_GetITStatus(TIM2,TIM_FLAG_Update) == 0);

//停止计数

TIM_SetAutoreload(TIM2,0);

//清中断标志

TIM_ClearITPendingBit(TIM2,TIM_FLAG_Update);

}



//延迟1ms

//最大65ms

void _delay_ms(uint8_t t)

{



if (t > 65)

{

t = 65;

}

_delay_us(t * 1000);

}

源代码2:

说明:定时器采用TIM3,时钟源为内部8M晶振,向上溢出模式.此定时器用在长时间计时,最小计时间隔为100us,故采用中断形式定时.

初始化代码:

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//中断NVIC设置：允许中断，设置优先级

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //更新事件

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

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //响应优先级1

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //允许中断

NVIC_Init(&NVIC_InitStructure); //写入设置



RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);

//重新将Timer设置为缺省值

TIM_DeInit(TIM3);

//采用内部时钟给TIM3提供时钟源

TIM_InternalClockConfig(TIM3);



timInitStruct.TIM_ClockDivision = TIM_CKD_DIV2; //定时器基准频率8MHz

timInitStruct.TIM_Prescaler = 800 - 1; //计数频率为100us跳转1次

timInitStruct.TIM_CounterMode = TIM_CounterMode_Up; //向上计数

timInitStruct.TIM_RepetitionCounter = 0;

timInitStruct.TIM_Period = 0; //这个值实际上就是TIMX->ARR，延时开始时重新设定即可



TIM_TimeBaseInit(TIM3, &timInitStruct);

//清溢出中断标志

TIM_ClearFlag(TIM3, TIM_FLAG_Update);

//禁止ARR预装载缓冲器

TIM_ARRPreloadConfig(TIM3, DISABLE);

//开启中断

TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);

TIM_Cmd(TIM3, ENABLE); //开启计数器

中断函数代码:

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//TIM3中断

void TIM3_IRQHandler(void)

{

if(TIM_GetITStatus(TIM3, TIM_IT_Update) == SET)

{

TIM3->ARR = 0;

//清中断溢出标志

TIM_ClearITPendingBit(TIM3,TIM_FLAG_Update);



//发送信号

Sig_Table.stop_require = 1;

}

}

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