plz help.. its about serial communication

hello guys...i am new to this forum...i saw many thread regarding serial communication betwwen pc and 8051 ..but it did not solve my problem.i want to send a string of 8 character continusly.and i m using interrupt here...in my program i want to display''we are in isr"on hyperterminal each time when isr is running...plz help me...here what i have done until now...its not workin and showing warning in printf ....


#include <REG51.H>
#include<stdio.h>
void send(unsigned char *);
sbit led=P1^0;
void inti_serialsetup();
unsigned char serialdata[]="ABCDEF";
void main()
{

inti_serialsetup();
send(serialdata);

while()
{
led=~led;
TH0=0XFF;
TL0=0X89;
TR0=1;
while(!TF0);
TF0=0;


}
}
void inti_serialsetup(void)
{

IE=0X90; //initialise serial interrupt
TMOD=0X21; //timer 0 in 16 bit and timer 1 in 8 bit mode
TH1=0XF6; //baud rate
SCON=0X50;
TR1=1;


}
void send(unsigned char *val)
{
unsigned char i=0;
for(i=0;i<7;i++)
{
SBUF=*val;

P1=SBUF;
val++;

}



}

void serialintrpt(void)interrupt 4
{
printf("\n we r in isr");
if(T1==1)
T1=0;
else
P1=SBUF;
RI=0;

}

Hi ami_20, you can't use printf in interrupt function. Because printf needs much time to execute, this will let interrupt unnormal.
You just need to write your own printf function.

thanx for reply.......then hw to write it?can you plz tel me??and hw to send string using interrupt?????gv me a clue....