定时器溢出中断,在程序设计中经常用到。在使用TIM1和TIM8溢出中断时,需要注意“TIM_TimeBaseStructure.TIM_RepetitionCounter=0;”,它表示溢出一次,并可以设置中断标志位。
TIM1_Interrupt_Initializtion(1000,72); //当arr=1000,psc=72时,则为1ms溢出一次就设置中断标志位,,误差为1us;
因为标准库默认TIM_TimeBaseStructure.TIM_RepetitionCounter=10,就表示溢出10次,才设置中断标志位。
若忘记设置,就是导致溢出时间不准确,严重会浪费调试时间。
时间久了,就会忘记,还是记录一下,加深记忆。
TIM1程序如下:
#include "Timer1.h"
u16 TIM1_MillisecondCounter;
u8 TIM1_SecondFlag;
void TIM1_Interrupt_Initializtion(u16 arr,u16 psc);//函数声明
//定时器1中断初始化
//APB2时钟为72MHz
//arr:自动重装值。
//psc:时钟预分频数
//TIM_CKD_DIV1:定时器时钟 = 输入频率
//TIM_CKD_DIV2:定时器时钟 = 输入频率/2
//TIM_CKD_DIV4:定时器时钟 = 输入频率/4
//TIM1溢出时间: arr*psc/72000000/TIM_CKD_DIVx
//TIM1_Interrupt_Initializtion(1000,72);//当arr=1000,psc=72时,则为1ms,误差为1us;
void TIM1_Interrupt_Initializtion(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
// u8 ch;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE); //使能定时器TIM1的APB2外设时钟
//定时器TIM1初始化
TIM_TimeBaseStructure.TIM_Period = arr-1; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc-1; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
//计算公式:arr*psc/72000000/1,当arr=1000,psc=72时,则溢出时间为1ms,误差为1us;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseStructure.TIM_RepetitionCounter=0;//TIM1溢出一次,则中断1次;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx的时间基数单位
TIM_SetCounter(TIM1,0); //设置TIM1的计数器值为0;
TIM_ClearFlag(TIM1, TIM_FLAG_Update); //清除TIM1溢出的待处理标志位
TIM_ClearITPendingBit(TIM1, TIM_IT_Update ); //清除TIM1中断的待处理位
TIM_ITConfig(TIM1,TIM_IT_Update,ENABLE ); //允许TIM1溢出产生中断
//中断优先级NVIC设置
//NVIC_PriorityGroup_4设置NVIC中断分组4:表示抢占优先级为4位,取值为0~15,没有响应优先级,取值为0
//NVIC_PriorityGroup_3设置NVIC中断分组3:表示抢占优先级为3位,取值为0~7,响应优先级只有1位,取值为0~1
//NVIC_PriorityGroup_2设置NVIC中断分组3:表示抢占优先级为2位,取值为0~3,响应优先级只有2位,取值为0~3
//NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);//设置系统中断优先级分组4
NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQn; //TIM1中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //设置抢占优先级为1
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //设置响应优先级为0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化NVIC嵌套向量中断控制寄存器
TIM_Cmd(TIM1, ENABLE);//使能TIM1外设
TIM1_MillisecondCounter=0;
}
//函数功能:TIM1每1ms溢出中断一次
void TIM1_UP_IRQHandler()
{
if (TIM_GetITStatus(TIM1,TIM_IT_Update) != RESET) //TIM1计数器溢出产生中断
{
TIM1_MillisecondCounter++;
if(TIM1_MillisecondCounter>=1000)
{
TIM1_MillisecondCounter=0;
TIM1_SecondFlag=1;
}
TIM_ClearITPendingBit(TIM1,TIM_IT_Update); //清除TIM1计数器的溢出中断标志;
}
}
TIM1头文件
#ifndef __Timer1_H
#define __Timer1_H
#include "stm32f10x.h" //使能uint8_t,uint16_t,uint32_t,uint64_t,int8_t,int16_t,int32_t,int64_t
extern u8 TIM1_SecondFlag;
extern void TIM1_Interrupt_Initializtion(u16 arr,u16 psc);
#endif
main,c程序
#include "stm32f10x.h" //使能uint8_t,uint16_t,uint32_t,uint64_t,int8_t,int16_t,int32_t,int64_t
#include "stdio.h" //getchar(),putchar(),scanf(),printf(),puts(),gets(),sprintf()
#include "USART1.h"
//注意:"USART1.h"要放在 "stdio.h" 包含文件之后,如果这个位置颠倒了,业不能打印浮点数。
#include "Timer1.h"
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);//设置系统中断优先级分组4
USART1_Serial_Interface_Enable(115200);
printf("\r\nCPU reset\r\n");
TIM1_Interrupt_Initializtion(1000,72);
//当arr=1000,psc=72时,则为1ms,误差为1us;
while(1)
{
if(TIM1_SecondFlag)
{
TIM1_SecondFlag=0;
printf("TIM1_SecondFlag=%u\r\n",TIM1_SecondFlag);
}
}
}