51单片机模拟计算机任务调度Demo

Abstract

使用定时器中断进行任务切换，每个任务按时间片(本测试不同任务相同时间片)运行，非死循环型任务。

Code

#include  

#define NULL ((void *)0)

sbit D1=P2^0;  
sbit D2=P2^1;

struct TASK
{
	signed char id;
	void (*taskFunction)(void);
};

unsigned char curTaskID;
struct TASK taskArr[2];

void CreatTask(void(*taskFun)(void))
{
	int i;
	for (i = 0; i < 2; i ++)
	{
			if (taskArr[i].id == -1)
			{
				taskArr[i].id = i;
				taskArr[i].taskFunction = taskFun;
				break;
			}
	}
}
void ExecuteTask(unsigned char id)
{
	taskArr[id].taskFunction();
}

void PopStack(unsigned char id)
{
	//now is blank
}

void PushStack(unsigned char id)
{
	//now is blank
}

void Task0(void)
{
	D1=~D1;  
}

void Task1(void)
{
	D2=~D2;  
}

void main(void)
{
  EA=1;	//Enable All Interrupt             
	ET0=1;	//Enable Interrupt timer0
	TMOD=0x01;	//Set timer0 mode = 2             
	TH0=(65536-46083)/256; //Set high 8 bits
	TL0=(65536-46083)%256; //Set low 8 bits
	
	taskArr[0].id = -1;
	taskArr[0].taskFunction = NULL;
	taskArr[1].id = -1;
	taskArr[1].taskFunction = NULL;
	
	CreatTask(Task0);
	CreatTask(Task1);
	
	curTaskID = 0;	//Set current task id
	TR0=1;	//Start timer0
	while(1)
	{
		ExecuteTask(curTaskID);
	}
}

void Timer0(void) interrupt 1 using 0   
{
	//Switch task ID
	PopStack(curTaskID);	//PopStack of Current Task,The Stack Can be a domain of Current Task better
	curTaskID ++;
	if (curTaskID == 2)
	{
		curTaskID = 0;
	}
	PushStack(curTaskID);	//PushStack of New Task,The Stack Can be a domain of New Task better
  TH0=(65536-46083)/256; 
	TL0=(65536-46083)%256; 
}