#include<reg51.h>

unsigned char r0=0,r1=0;
unsigned char a[10]={0XC0,0XF9,0XA4,0XB0,0X99,0X92,0X82,0XF8,0X80,0X90};
sbit P37=0XB7;
void main()
{
	TMOD=0X20;
	TCON=0X00;
	SCON=0X50;
	PCON=0X00;
	TH1=0X00;
	TL1=0X00;
	IP=0X08;
    P37=0;
    P0=r1^0XFF;
	IE=0X98;
	TR1=1;
	SBUF=r0;
	while(1)
	{
	}
}

void send(void) interrupt 4
{      
	if(RI==1)
	{r0=SBUF;
	RI=0;
	}
	else
	{
		SBUF=r0;
		TI=0;
	}
    r1++;
    if(r1==256)
    r1=0; 
    P0=r1^0XFF;
}