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 = P1^0;
sbit LED1 = P1^1;
sbit LED2 = P1^2;
sbit LED3 = P1^3;

/*main主函数*/
void main(void)
{
unsigned char i;
os_timer0_init();
EA = 1; //开总中断

while(1)
{
for(i=0;i<MAX_TASK;i++)
if (task_delay[i]==0) {run(task[i]); break;} //任务优先级调度
}
}

void task0(void)
{
LED0 = !LED0;
task_delay[0] = TASK_DELAY0;
}

void task1(void)
{
LED1 = !LED1;
task_delay[1] = TASK_DELAY1;
}

void task2(void)
{
LED2 = !LED2;
task_delay[2] = TASK_DELAY2;
}

void task3(void)
{
static unsigned char state=0;
switch (state)
{
case 0:
LED3 = !LED3;
state = 1;
task_delay[3] = TASK_DELAY3;
break;

case 1:
LED3 = !LED3;
state = 2;
task_delay[3] = TASK_DELAY3*2;
break;

case 2:
LED3 = !LED3;
state = 0;
task_delay[3] = TASK_DELAY3*4;
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=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
TMOD = (TMOD & 0XF0) | 0X01; //定时器0工作在模式1，16Bit定时器模式
TH0 = (65536-CLOCK/TIME_PER_SEC/12) / 256; //CRY_OSC,TIME_PER_SEC在easycfg.h中配置
TL0 = (65536-CLOCK/TIME_PER_SEC/12) % 256;
TR0 =1;
ET0 =1; //开启定时器和中断
}

// 系统OS定时中断服务
void os_timer0(void) interrupt 1
{
unsigned char i;
TH0 = (65536-CLOCK/TIME_PER_SEC/12) / 256; //CRY_OSC,TIME_PER_SEC在easycfg.h中配置
TL0 = (65536-CLOCK/TIME_PER_SEC/12) % 256;
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。
}

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