(Hoping this is a new subject, so I am starting a new thread)

Hi all, just look into the following code:

/*globals*/
char packet[10];
unsigned char byte_no=0;
      
bit bdata txbit=0, rxbit=0, end_comm=0;

void serial(void) interrupt 4
{
       if(TI)    txbit=1;
       if(RI)
       {
            rxbit=1;
            comhandle();
       }
}

void comhandle(void)
{
      packet[byte_no]=SBUF;
      byte_no++;  //suspicion
      if(byte_no==9)   
      {
           byte_no=0; 
           end_comm=1;
      }
}

void main(void)
{...}
      

What happens is that, the first byte of 10 byte serial packet never gets stored in packet[0]. What I suspect is, byte_no++ instruction gets evaluated in the first run, before the main function is called. So when a byte arrives, byte_no has value of 1. Will this happen? comhandle() function is supposed to run only when the microcont receives a serial byte. Any suggestions?

Thanks and Regards,
Vignesh