STM32定时器溢出模式计时设置

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:

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:

//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:

//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:

//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;
    }
}