Easy51RTOS入门级初略分析

  1 main.c
  2 
  3 #include "reg51.h"
  4 #include "os_cfg.h"
  5 #define TASK_DELAY0 TIME_PER_SEC/1 //任务执行频度为1Hz
  6 #define TASK_DELAY1 TIME_PER_SEC/2 //任务执行频度为2Hz
  7 #define TASK_DELAY2 TIME_PER_SEC/10 //任务执行频度为10Hz
  8 #define TASK_DELAY3 TIME_PER_SEC/20 //任务执行频度为20Hz
  9 
 10 void (* code task[])() = {task0,task1,task2,task3};
 11 
 12 sbit LED0 = P1^0;
 13 sbit LED1 = P1^1;
 14 sbit LED2 = P1^2;
 15 sbit LED3 = P1^3;
 16 
 17 /*main主函数*/
 18 void main(void)
 19 {
 20 unsigned char i;    
 21 os_timer0_init();
 22 EA = 1;    //开总中断
 23 
 24 while(1)
 25 {
 26 for(i=0;i<MAX_TASK;i++) 
 27 if (task_delay[i]==0) {run(task[i]); break;} //任务优先级调度    
 28 }
 29 }
 30 
 31 
 32 void task0(void)
 33 { 
 34 LED0 = !LED0; 
 35 task_delay[0] = TASK_DELAY0;
 36 }
 37 
 38 void task1(void)
 39 { 
 40 LED1 = !LED1; 
 41 task_delay[1] = TASK_DELAY1;
 42 }
 43 
 44 void task2(void)
 45 { 
 46 LED2 = !LED2; 
 47 task_delay[2] = TASK_DELAY2;
 48 }
 49 
 50 void task3(void)
 51 { 
 52 static unsigned char state=0;
 53 switch (state)
 54 {
 55 case 0:
 56 LED3 = !LED3; 
 57 state = 1;
 58 task_delay[3] = TASK_DELAY3;
 59 break;
 60 
 61 case 1:
 62 LED3 = !LED3; 
 63 state = 2;
 64 task_delay[3] = TASK_DELAY3*2;
 65 break;
 66 
 67 case 2:
 68 LED3 = !LED3; 
 69 state = 0;
 70 task_delay[3] = TASK_DELAY3*4;
 71 break;
 72 
 73 default:
 74 break;
 75 }    
 76 }
 77 
 78  
 79 
 80 os_cfg.h
 81 
 82 #include "reg51.h"
 83 #define TIME_PER_SEC 200 //定义任务时钟频率，200Hz
 84 #define CLOCK 22118400    //定义时钟晶振，单位Hz
 85 #define MAX_TASK 4    //定义任务数量
 86 extern void task0(void);
 87 extern void task1(void);
 88 extern void task2(void);
 89 extern void task3(void);
 90 extern unsigned char task_delay[MAX_TASK];
 91 extern void run(void (*ptask)());
 92 extern void os_timer0_init(void);
 93 
 94  
 95 
 96 os_cfg.c
 97 
 98 #include "os_cfg.h"
 99 unsigned char task_delay[MAX_TASK];
100 
101 //定时器0初始化
102 void os_timer0_init(void)
103 {
104 unsigned char i;
105 for(i=0;i<MAX_TASK;i++) task_delay[i]=0; //赋初值task_delay[0]=0，task_delay[1]=0，task_delay[2]=0，task_delay[3]=0 
106 TMOD = (TMOD & 0XF0) | 0X01; //定时器0工作在模式1，16Bit定时器模式 
107 TH0 = (65536-CLOCK/TIME_PER_SEC/12) / 256;    //CRY_OSC,TIME_PER_SEC在easycfg.h中配置
108 TL0 = (65536-CLOCK/TIME_PER_SEC/12) % 256; 
109 TR0 =1; 
110 ET0 =1;    //开启定时器和中断
111 }
112 
113 // 系统OS定时中断服务
114 void os_timer0(void) interrupt 1
115 {
116 unsigned char i;
117 TH0 = (65536-CLOCK/TIME_PER_SEC/12) / 256;    //CRY_OSC,TIME_PER_SEC在easycfg.h中配置
118 TL0 = (65536-CLOCK/TIME_PER_SEC/12) % 256; 
119 for(i=0;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。 
120 }
121 
122 void run(void (*ptask)())
123 { 
124 (*ptask)(); 
125 }