How to re - send data to the interfaced device

Any one who can help

i am having a problem on how to re - enter data to P89V51RD2 micro controller re- send to the interfaced device in which whose main function codes are inside a while(1) that means always true . my main function is looks like this void main ()
{ variable declaration

lcdInit(); lcdClear(); lcdGotoXY(0,0); //lcdPrint("::::::::::::::::::::"); //lcdGotoXY(0,1); lcdPrint(":: ::"); //lcdGotoXY(0,3); //lcdPrint("::::::::::::::::::::"); delayms(5000);
while (1)
{

then every thing here function that scans the keypad function that sends to LCD function that sends to the interfaced device

}

}
i am using keil uVision 3 as my compiler . my main problem is how to re- send data to the interfaced device with out resetting it .

Thanks for u help