//头文件
#include
#include
//宏定义
#defineuchar unsigned char
#define uint unsigned int
#define TN 65436
//进程1，2，3执行时间之比为 T1：T2：T3 （时间单位us）
#define TN1 62536 //1个进程循环周期内进程1执行的时间T1us TN1=(65536-T1)
#define TN2 55536 //1个进程循环周期内进程2执行的时间T2us TN2=(65536-T1)
#define TN3 60536 //1个进程循环周期内进程3执行的时间T3us TN3=(65536-T1)
//
#define N1 10 // 进程1的延时参数
#define N2 10 // 进程2的延时参数
#define N3 10 // 进程3的延时参数

//定义全局变量
uint address1,address2,address3;
uchar test1_1=0,test2_1=0,test3_1=0,PID=1;
//各进程的标志位，是否为第一次执行；PID进程号；
uint ac1,ac2,ac3; //, PC_Next; 各进程的初始地址寄存器.
//test1 的参数 由于进程切换时 没有保存普通变量，
//所以各进程的普通参数需要定义成全局变量.
uint m1,i1,j1,k1;
uchar table1[4];
//test2 的参数
int m2,i2,j2,k2;
uchar table2[4];
//test3 的参数
int m3,i3,j3,k3; //
uchar table3[4];

//声明
//unsigned int Get_Next_PC(void);//调用子程序，获取PC
void chushihua(void); //初始化函数
void test1(void); //进程一
void test2(void);
void test3(void);

//main函数
void main(void)
{
// PC_Next=Get_Next_PC();
chushihua();
ac1=(unsigned int)(test1); //获取进程1的入口地址
ac2=(unsigned int)(test2);//获取进程2的入口地址
ac3=(unsigned int)(test3); //获取进程3的入口地址
//常规任务
while(1);
}

//初始化时钟
void chushihua(void)
{
TMOD=0x01;//
EA=1;//
ET0=1;//
TH0=TN/256;
TL0=TN%6;
TR0=1;
}

//中断处理，进程调度
void time0() interrupt 1 using 0
{
TR0=0;
//进程顺序分配
PID++;
if(PID==4)
{PID=1;}
//进程调度
switch(PID)
{
case 1:
if(test3_1!=0)
{ //保存现场，还回地址
address3=*((unsigned char *)(SP-4));//PC的高字节
address3 <<= 8;
address3+=*((unsigned char *)(SP-5)); //PC的低字节
table3[0]=*((unsigned char *)(SP)); //现场保护
table3[1]=*((unsigned char *)(SP-1)); //现场保护
table3[2]=*((unsigned char *)(SP-2)); //现场保护
table3[3]=*((unsigned char *)(SP-3)); //现场保护
}
if(test1_1==0)
{ //执行新进程
test1_1=1;
*((unsigned char *)(SP-4))=ac1>>8; //PC的高字节
*((unsigned char *)(SP-5))=ac1 & 0x00ff; //PC的低字节
}
else
{ //执行新进程，恢复现场
*((unsigned char *)(SP-4))=address1>>8; //PC的高字节
*((unsigned char *)(SP-5))=address1 & 0x00ff; //PC的低字节
*((unsigned char *)(SP))=table1[0]; //现场恢复
*((unsigned char *)(SP-1))=table1[1]; //现场恢复
*((unsigned char *)(SP-2))=table1[2]; //现场恢复
*((unsigned char *)(SP-3))=table1[3]; //现场恢复
}
TH0=TN1/256;
TL0=TN1%6;
TR0=1;
break;

case 2:
if(test1_1!=0)
{ //保存现场，还回地址
address1=*((unsigned char *)(SP-4)); //PC的高字节
address1 <<= 8;
address1+=*((unsigned char *)(SP-5)); //PC的低字节
table1[0]=*((unsigned char *)(SP)); //现场保护
table1[1]=*((unsigned char *)(SP-1));//现场保护
table1[2]=*((unsigned char *)(SP-2));//现场保护
table1[3]=*((unsigned char *)(SP-3)); //现场保护
}
if(test2_1==0)
{ //执行进程2
test2_1=1;
*((unsigned char *)(SP-4))=ac2>>8; //PC的高字节
*((unsigned char *)(SP-5))=ac2 & 0x00ff; //PC的低字节
}
else
{ //执行进程2，恢复现场
*((unsigned char *)(SP-4))=address2>>8;//PC的高字节
*((unsigned char *)(SP-5))=address2 & 0x00ff; //PC的低字节
*((unsigned char *)(SP))=table2[0]; //现场恢复
*((unsigned char *)(SP-1))=table2[1]; //现场恢复
*((unsigned char *)(SP-2))=table2[2]; //现场恢复
*((unsigned char *)(SP-3))=table2[3]; //现场恢复
}
TH0=TN2/256;
TL0=TN2%6;
TR0=1;
break;

case 3:
if(test2_1!=0)
{ //保存现场，还回地址
address2=*((unsigned char *)(SP-4)); //PC的高字节
address2 <<= 8;
address2+=*((unsigned char *)(SP-5)); //PC的低字节
table2[0]=*((unsigned char *)(SP)); //现场保护
table2[1]=*((unsigned char *)(SP-1)); //现场保护
table2[2]=*((unsigned char *)(SP-2)); //现场保护
table2[3]=*((unsigned char *)(SP-3)); //现场保护
}
if(test3_1==0)
{ //执行进程3
test3_1=1;
*((unsigned char *)(SP-4))=ac3>>8;//PC的高字节
*((unsigned char *)(SP-5))=ac3 & 0x00ff; //PC的低字节
}
else
{ //执行进程3，恢复现场
*((unsigned char *)(SP-4))=address3>>8; //PC的高字节
*((unsigned char *)(SP-5))=address3 & 0x00ff; //PC的低字节
*((unsigned char *)(SP))=table3[0]; //现场恢复
*((unsigned char *)(SP-1))=table3[1]; //现场恢复
*((unsigned char *)(SP-2))=table3[2]; //现场恢复
*((unsigned char *)(SP-3))=table3[3]; //现场恢复
}
TH0=TN3/256;
TL0=TN3%6;
TR0=1;
break;
default:
TH0=TN/256;
TL0=TN%6;
TR0=1;
break;
}
}

//进程一 P1演示二进制加法死循环
void test1(void)
{
while(1)
{

for(i1=0;i1<256;i1++)
{
for(k1=0;k1<=N1;k1++)
{for(j1=0;j1<=20;j1++)
for(m1=0;m1<=113;m1++);} // 约1ms*T1/T1+T2+T3
P1=i1;
//P2=0x0;
}
}
}

//进程二P2演示二进制加法死循环
void test2(void)
{
while(1)
{

for(i2=0;i2<256;i2++)
{
for(k2=0;k2<=N2;k2++)
{for(j2=0;j2<=20;j2++)
for(m2=0;m2<=113;m2++);}
P2=i2;
}
}
}

//进程三 P0口演示二进制加法死循环 进程3的延时参数
void test3(void)
{
while(1)
{

for(i3=0;i3<256;i3++)
{
for(k3=0;k3<=N3;k3++)
{for(j3=0;j3<=20;j3++)
for(m3=0;m3<=113;m3++);}
P0=i3;
}
}
}