I recently bought the LAB-X2 (by microEngineering Labs) with a 4Mhz 16f877.
 My development tools are listed below.  The problem: the code (attached
below), when in the PIC, fails to jump to the "sendData" subroutine.
 Although the code works properly in the emulator.  Has anyone else had
this problem and solved it?  Could the code generated by the cc5x compiler
be effected by the bootloader?  I have been researching this problem for
about a week and have found nothing useful.  I am hoping someone on the
list has a solution.


Compiler: cc5x  V. 3.1C
Bootloader: microEngineering Labs, Target firmware V 1.0
IDE: MPLab 5.11.00
Code: A rs232 example problem provided by the maker of cc5x.


// *********************************************************
/*
  SERIAL COMMUNICATION (RS232)
  ============================

  Using 9600 baud, one stop bit, no parity.
  Baudrate 9600 baud => 104.167 microsec. per bit
  TMR0 counts each 8th microsec. => 13.02 steps per bit
*/

#pragma chip PIC16F877

#pragma cdata[0] = 0x0180 + 0x0A   // CLRF PCLATH
#pragma resetVector 1 // start address for user program
// --------------------------------------------

#define _4_MHz    /* 4 MHz system clock */
// #define UseTMR0

#pragma bit RS232_out @ PORTC.6
#pragma bit RS232_in  @ PORTC.7

#ifdef _4_MHz
 #define   TimeStartbit    4
 #define   BitTimeIncr     13
#endif

char bitCount, limit;
char serialData;

#ifdef _4_MHz
 #ifdef UseTMR0
   #define delayStart   limit = TMR0;
   #define delayOneBit      \
     limit += BitTimeIncr;  \
     while ( limit != TMR0) \
         ;
 #else
   #define delayStart   /* empty */
   #define delayOneBit  {      \
        char ti;               \
        ti = 30;               \
        do ; while( --ti > 0); \
        nop();                 \
     }  /* total: 5 + 30*3 - 1 + 1 + 9 \
           = 104 microsec. at 4 MHz */
 #endif
#endif
//
//-------------------------------------------
//
void sendData( char dout)
/* sends one byte */
{
    PORTB.2 = 0;  // Test LED

    RS232_out = 0;  /* startbit */
    delayStart
    for ( bitCount = 9; ; bitCount--)  {
        delayOneBit
        if ( bitCount == 0)
            break;
        Carry = 1;  /* incl. stopbit */
        dout = rr( dout);
        RS232_out = Carry;
    }
    PORTB.1 = 0;  // Test LED
}
//
//--------------------------------------------
//
#define NText 12
char text( char W)
{

   skip(W);
   #pragma return[NText] = "Hello world!"
}
//
//-------------------------------------------
//-------------- main ----------------------
//
void main( void)
{
    char i,j;
    PORTB = 0b.0000.0001; // xxxx xxxx
    TRISB = 0b.0000.0000; // xxxx xxxx

    PORTC = 0b.1111.1111; // xxxx xxxx
    TRISC = 0b.1011.1111; // xxxx xxxx
    OPTION = 2;   // prescaler divide by 8

  PORTB.1 =1;

//    for ( i = 0; i < NText; i++);
  PORTB.2 = 1;

    for ( i = 0; i < NText; i++)
          {
          j = text(i);
          sendData( j );  /* text string */
          }

  WaitNextIO:
    while ( RS232_in == 1)
        ;


  Start_RS232:
    /* sampling once per bit */
    TMR0 = 0;
    limit = TimeStartbit;
    while ( limit != TMR0)
        ;
    if ( RS232_in == 1)
        goto StartBitError;

    bitCount = 8;
    do  {
        limit += BitTimeIncr;
        while ( limit != TMR0)
            ;
        Carry = RS232_in;
        serialData = rr( serialData);  /* rotate carry */
    } while ( -- bitCount > 0);

    limit += BitTimeIncr;
    while ( limit != TMR0)
        ;
    if ( RS232_in == 0)
        goto StopBitError;

    /* 'serialData' can be processed here */
    /* NOTE: limited time (40 - 50 microsec.) */
    goto WaitNextIO;

  StopBitError:
    /* RS232 stopbit error,
       waiting while line is low */
    while ( RS232_in == 0)
        ;
  StartBitError:
    goto WaitNextIO;
}

// *********************************************************




Regards,
Brendon
______________________________________________________________
Brendon R. Holt, Ph.D.                E-mail: drholt@flash.net

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