Problem with TXD interrupt

[Alex]

Hello to everybody
I am using PIC16F877
and trying to write just a very simple program to send some characters through the RS232 to PC using interrupts just to start with.
So, could anybody help me and tell why the following code does not work
Thank you very much

#pragma device PIC16F877

#USE standard_IO(C)
#use delay (clock=4000000)

#include "SFR.h"
#include "DEFS.h"

void init(void);
void TXD_isr();

int index = 2;
unsigned char a;
unsigned char arr[] = {'a','b','c'};

//------------------------------------------------

void main(void)
{
init();

while(1)
{
if (ENABLE)
{
TXREG = a;
ENABLE = 0;
}
}
}
//---------------------------------------------------
#INT_TBE
void TXD_isr(void)
{

int i;
a = arr[i];
i++;

if (i>index)
{
i = 0;
}
ENABLE = 1;
PIR1bits.SSPIF = 0 ;

}
void init(void)
{
SET_TRIS_C(0xFE);
TXSTA = 0x26 ;
RCSTA = 0x90 ;
SPBRG = 25; // set_uart_speed(9600);

TXD_IE = 1 ;
SERIAL_IE = 1 ;

a = 'm';

ENABLE = 1 ;
INTCONbits.PEIE = 1 ;
enable_interrupts(INT_TBE);
enable_interrupts(GLOBAL);

[Mark]

#pragma device PIC16F877 <- no pragma

TXD_IE = 1 ; <- is this the same enable_interrupts(INT_TBE); ?
SERIAL_IE = 1 ; <- What does this do?

INTCONbits.PEIE = 1 ; <- Why are you mixing methods of enabling ints? This does the same thing enable_interrupts(GLOBAL);

[Guest]

TXD_IE = 1 ; <- is this the same enable_interrupts(INT_TBE); ?
yes

SERIAL_IE = 1 ; <- What does this do?
SERIAL_IE = PIE1bits.SSPIE


INTCONbits.PEIE = 1 ; <- Why are you mixing methods of enabling ints? This does the same thing enable_interrupts(GLOBAL);

I understood that enable_interrupts(GLOBAL); enables only GIE bit
Is not it?

[alexbilo]

[alexz]

Thank you for the explanation Alex
But it did not solve the problem
_________________
Alex

[alexz]

The program works fine wen I run it step by step
But it does not do anything when I run it normally
_________________
Alex

[PCM programmer]

CCS has an example program for #int_tbe called EX_STISR.C.
That file is in this folder on your computer:
c:\Program Files\Picc\Examples

I also once wrote an example for #int_tbe. It's here:
http://www.ccsinfo.com/wwwboard/messages/1848.html

[Guest]

I have done it exactly the same way.
the problem is that the RBE interrupt occurs all the time
and the program never riches the main loop

[Mark]