18f452 #INT_TBE Problem

[micro]

I wrote a simple code snipped like in the below. I want to use TBE interrupt but some problem. When I wrote the code in below, interrupt routine works (porta turn completely high level) but "putc('A')" function does not work. However, When I disable interrupts, "putc" works. Why does this problem occure?



#include <18f458.h>
#include <string.h>
//#device *=16
#fuses H4,NOWDT,NOPROTECT,NOBROWNOUT,NOPUT,NOLVP
#use delay(clock=40000000)
#use rs232 (baud=9600, xmit=PIN_C6, rcv=PIN_C7,ERRORS)

#INT_TBE
void PumpTransmitInt(void)
{

output_a(0xFF);

}


void main(void)
{
enable_interrupts(INT_TBE);
enable_interrupts(GLOBAL);

putc('A');

while(1);

}

[Mark]

I think you might be a bit confused about what the TBE int is. It is a transmit interrupt. This is where you normally load the value to be transmitted. The interrupt fires whenever the transmit register is empty. It your case, it is going to fire all the time. Constantly, over and over and over. That is why nothing appears to work after the ints are enabled.