//115.2k串行口通信程序，校驗(yàn)方式為簡(jiǎn)單雙向校驗(yàn),
//而且是必要的，因?yàn)槿魏尾捎弥袛?、crc等的方法
//均很難保證速度和避免錯(cuò)誤.
//總體速度5KB/秒

//單片機(jī)程序
//使用22.1184晶振
unsigned char time,b_break,b_break_3;
//35.555ms
void int_t0(void) interrupt 1 {
 TH0=0;
 if ((++b_break_3)>2) b_break=1;
 time++;
}

//

unsigned char rec(void) {
 TH0=0;b_break_3=0;b_break=0;
 while (RI==0) {
  if (b_break) return(1);  //等待pc發(fā)送100ms超時(shí)
 }
 RI=0;
 SBUF=SBUF;
 return(SBUF);
}
/*返回1表示失敗*/
bit sen(unsigned char d) {
 SBUF=d;
 TH0=0;b_break_3=0;b_break=0;
 while (RI==0) {
  if (b_break) return(1);  //等待pc送回相同字節(jié)數(shù)據(jù)，100ms超時(shí)
 }
 RI=0;
 if (SBUF!=d) return(1);
 return(0);
}

void main(void) {
 unsigned int i;
 unsigned char d;
 EA=1;
 SCON=0xd8;PCON=0x80;
 TMOD=0x21;
 TL1=TH1=0xff;TR1=1;
 TH0=0;ET0=TR0=1;
 while (1) {
  d=rec();
  if ((!b_break)&&(d==0x55)) {
   d=rec();
   if (!b_break) {
    if (d==0xaa) {
     //接收到pc送來(lái)的要求發(fā)送指令0xaa55
     for (i=0;i<1000;i++) {
      if (sen(i)) {
       //發(fā)送錯(cuò)誤
       break;
      }
     }
    } else if (dd==0xaa) {
     //接收到pc送來(lái)的要求接收指令0xaaaa
     for (i=0;i<1000;i++) {
      d=rec();
      if (!b_break) {
       //正確接收處理
      } else {
       //接收錯(cuò)誤處理
       break;
      }
     }
    }
   }
  }
 }
}

//電腦程序tc2.0
＃i nclude "stdio.h"
＃i nclude "dos.h"
＃i nclude "process.h"
＃i nclude "string.h"
＃i nclude "conio.h"
＃i nclude <dir.h>
unsigned char time_out;

void init_com1(void) {
 outportb(0x3fb,0x80);
 outportb(0x3f8,1);
 outportb(0x3f9,0x0);
 outportb(0x3fb,0x3);
}
void sen_com1(unsigned char d) {
 long i;
 time_out=0;
 while (!(inportb(0x3fd)&0x20));
 outportb(0x3fd,0x0);
 outportb(0x3f8,d);
 i=clock();
 while (1) {
  if (clock()>(i+8)) {time_out=1;return;}
  if ((inp(0x3fd)&0x1)==1) break;
 }
 if (inp(0x3f8)!=d) {time_out=2;return;}
}
unsigned char rec_com1(void) {
 long i;
 unsigned char d;
 time_out=0;
 i=clock();
 while (1) {
  if (clock()>(i+8)) {time_out=1;return(0);}
  if ((inp(0x3fd)&1)==1) break;
 }
 d=inp(0x3f8);
 while (!(inportb(0x3fd)&0x20));
 outportb(0x3fd,0x0);
 outportb(0x3f8,d);
 return(d);
}
void main(void) {
 int i;
 long st;
 init_com1();
 st=clock();
 sen_com1(0xaa);
 if (time_out) {printf("CPU not ready!");exit(-1);}
 sen_com1(0xaa);
 if (time_out) {printf("CPU not ready!");exit(-1);}
 for (i=0;i<1000;i++) {
  sen_com1(i);
  if (time_out) {printf("CPU not ready!");exit(-1);}
 }
 printf("Total use %3.2f S.",(clock()-st)/18.2);
 exit(1);
}