51

来自「计算机控制系统」· 代码 · 共 36 行

#include    <reg51.h>
#include    <absacc.h>
#define		out_port		XBYTE[0xcfa0]

void delay(unsigned int t)
  {
   for(;t>0;t--);
  }
void main(void)
  {
   char transmit = 0,receiv;
   TMOD = 0x20;
   TL1 = 0xf2;
   TH1 = 0xf2;
   PCON = 0;
   SCON = 0x50;
   TR1 = 1;
   while(1)
     {
      TI = 0;
	  SBUF = transmit;
      while(RI)
	    {
		 RI = 0;
		 receiv = SBUF;
		 if(receiv<8)
		   out_port = ~((1<<receiv));
		 else
		   out_port = ~((1<<(15-receiv)));
	    }	
	  transmit++;
	  if(transmit==16) transmit = 0;
	  delay(3000);
     }
  }