Hello, I am trying to receive a character that resetee a record and it does not work, use keil.
This is the code.

#include <Reg52.h> // se incluyen archivos externos
#include <stdio.h>

char uart_data=0x30;
void Entrada();
void Salida();
sbit s1 = P2^0;
sbit s2 = P2^1;
sbit s3 = P0^0;

char R1;
long int E=0x00;
long int S=0x00;

void main(void)
{
#ifndef MONITOR51
SCON = 0x52;
TMOD |= 0x20;
TH1 = 0xFD;
TL1 = 0xFD;
TR1 = 1;
TI = 1;
ES = 1;
EA = 1;
#endif
while(1);

void serial_IT(void) interrupt 4
{
if (RI==1)
{
RI = 0;
uart_data = SBUF;
if(uart_data==0x00)
E = 0;
TI = 1;
SBUF = uart_data;
}
else TI = 1;
if(s1==0)
{
while(s2==1);
if(s3==1)Entrada();
while(s1==0 || s2==0);
}
if(s2==0)
{
while(s1==1);
if(s3==0)Salida();
while(s1==0 || s2==0);
}
}


void Entrada(void)
{
E++;
printf ("\n%10li",E);
}

void Salida(void)
{
S++;
printf ("\n%10li",S);
}
Helpme please.
Thanks