Easy51RTOS入门级初略分析

 main.c

 #include "reg51.h"
 #include "os_cfg.h"
 #define TASK_DELAY0 TIME_PER_SEC/1 //任务执行频度为1Hz
 #define TASK_DELAY1 TIME_PER_SEC/2 //任务执行频度为2Hz
 #define TASK_DELAY2 TIME_PER_SEC/10 //任务执行频度为10Hz
 #define TASK_DELAY3 TIME_PER_SEC/20 //任务执行频度为20Hz

 void (* code task[])() = {task0,task1,task2,task3};

 sbit LED0 = P1^;
 sbit LED1 = P1^;
 sbit LED2 = P1^;
 sbit LED3 = P1^;

 /*main主函数*/
 void main(void)
 {
 unsigned char i;
 os_timer0_init();
 EA = ;    //开总中断

 while()
 {
 for(i=;i<MAX_TASK;i++)
 if (task_delay[i]==) {run(task[i]); break;} //任务优先级调度
 }
 }

 void task0(void)
 {
 LED0 = !LED0;
 task_delay[] = TASK_DELAY0;
 }

 void task1(void)
 {
 LED1 = !LED1;
 task_delay[] = TASK_DELAY1;
 }

 void task2(void)
 {
 LED2 = !LED2;
 task_delay[] = TASK_DELAY2;
 }

 void task3(void)
 {
 static unsigned char state=;
 switch (state)
 {
 case :
 LED3 = !LED3;
 state = ;
 task_delay[] = TASK_DELAY3;
 break;

 case :
 LED3 = !LED3;
 state = ;
 task_delay[] = TASK_DELAY3*;
 break;

 case :
 LED3 = !LED3;
 state = ;
 task_delay[] = TASK_DELAY3*;
 break;

 default:
 break;
 }
 }

 os_cfg.h

 #include "reg51.h"
 #define TIME_PER_SEC 200 //定义任务时钟频率，200Hz
 #define CLOCK 22118400    //定义时钟晶振，单位Hz
 #define MAX_TASK 4    //定义任务数量
 extern void task0(void);
 extern void task1(void);
 extern void task2(void);
 extern void task3(void);
 extern unsigned char task_delay[MAX_TASK];
 extern void run(void (*ptask)());
 extern void os_timer0_init(void);

 os_cfg.c

 #include "os_cfg.h"
 unsigned char task_delay[MAX_TASK];

 //定时器0初始化
 void os_timer0_init(void)
 {
 unsigned char i;
 for(i=;i<MAX_TASK;i++) task_delay[i]=; //赋初值task_delay[0]=0，task_delay[1]=0，task_delay[2]=0，task_delay[3]=0
 TMOD = (TMOD & 0XF0) | 0X01; //定时器0工作在模式1，16Bit定时器模式
 TH0 = (-CLOCK/TIME_PER_SEC/) / ;    //CRY_OSC,TIME_PER_SEC在easycfg.h中配置
 TL0 = (-CLOCK/TIME_PER_SEC/) % ;
 TR0 =;
 ET0 =;    //开启定时器和中断
 }

 // 系统OS定时中断服务
 void os_timer0(void) interrupt
 {
 unsigned char i;
 TH0 = (-CLOCK/TIME_PER_SEC/) / ;    //CRY_OSC,TIME_PER_SEC在easycfg.h中配置
 TL0 = (-CLOCK/TIME_PER_SEC/) % ;
 for(i=;i<MAX_TASK;i++) if(task_delay[i]) task_delay[i]--;    //每节拍对任务延时变量减1 ，减至 0 后，任务就绪。
 }

 void run(void (*ptask)())
 {
 (*ptask)();
 }