I want to do some Lame Multiprocessing.....

this is the sample code i want to do inside the Recive interrupt but its not the exact one because there might be some variations

int i=1;//global variable which is to be compared

void xyz (void) interrupt 4
{
if (R1)
{
if (SBUF==i)
{
/*My code probabally the Printf statememt*/
}
}
}

this is the sample code i want to do inside the Recive interrupt but its not the exact one because there might be some variations

int i=1;//global variable which is to be compared

void xyz (void) interrupt 4
{
if (R1)
{
if (SBUF==i)
{
/*My code probabally the Printf statememt*/
}
}
}

int i=1;//global variable which is to be compared

void xyz (void) interrupt 4
{
   if (R1)
   {
      if (SBUF==i)
      {
         /*My code probabally the Printf statememt*/
      }
   }
}

It would be a Really Bad Idea to call printf from inside your ISR...!

:-0

YOu have written that it would be really bad idea to call printf function from ISR so could you please tell me how to send multiple charecters or integers from SBUF ?

http://www.keil.com/download/docs/200.asp

"It would be a Really Bad Idea to call printf from inside your ISR...!

:-0
"

I agree with Andy. printf() is horribly large and slow on any microcontroller, especially in a 8051.
You should never do lengthy operations inside a interrupt handler, to preserve system interrupt latency (the system response time for a interrupt).

Instead, you can prepare a buffer (e.g. unsigned char buf[]) with the ascii characters you want to send, and then directly feed the USART tx register with the characters, one at a time. The USART interrupt will be triggered on completion of each character transmission, and you can then get the next char from your buffer and send it to the USART, returning from the ISR. This takes just a few microseconds per char, and your main software can run while the USART is sending the char by the slow serial line.