WHY NEVER STOPS??

[ccmcca]

#include "mainbalanza.h"
#int_RDA
RDA_isr()
{
printf("-INTERRUPT-");
delay_ms(1000);
}
void main()
{

ini();
delay_ms(10);
printf("------------------------------------\n\r");
printf("Running...\n\r");
printf("------------------------------------\n\r");
while(1)
delay_ms(1000);
}



Hello! My problem is that this code is doing this

------------------------------------
Running...
------------------------------------
-INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--IN
TERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTER
RUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUP
T--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT--INTERRUPT-

And never stop...
I have to clean the interrupt or something?

[rberek]

Yes, you have to clear the interrupt or else you will re-enter the ISR as soon as you exit it. Using a getc() inside the ISR will clear the interrupt.

I'm also assuming that the delay_ms(1000) inside the ISR is for debugging purposes only.

[Ttelmah]

Actually, let's just 'clear this up'. Several people refer to 'clearing the interrupt', but this is _not_ what reading the character does!.
Basically, interrupts have a 'multi layer' hardware structure. There is a hardware 'event', which triggers the interrupt, and then the interrupt 'flag', set by this event. Now the interrupt handler _itself_, 'clears' the interrupt flag (CCS do this for you, unless you specify the interrupt with 'noclear'). However unless the character is read, the buffer is left 'full', and this will automatically 'set' the flag again, as soon as it is cleared.
What 'clearing' you have to do, varies with different interrupts. So (for instance), the 'INT0' interrupt, has it's 'hardware event', triggered only by the 'edge' of the incoming signal (rather than by a level). On this, once you clear the interrupt flag, nothing else is needed, and the interrupt will only trigger when the next active 'edge' is seen. Since this is done for you by CCS, no 'clearing' is apparently needed. However the serial 'receive' interrupt, and the 'port B change' interrupt, are both 'static' events, and will keep re-triggering, till the 'source' of the event is cleared (reading port B, or reading the incoming character).
So for the serial receive interrupt, _two_ things have to be cleared. First the 'source' (reading the character), and then the interrupt flag as well (but this is done for you).
There is also a third situation, the 'serial transmit' interrupt. On this, if you have no more data to send, the transmit buffer will remain empty, and the interrupt will keep re-triggering. Hence this if one of the few interrupts, where you must disable the interrupt itself inside the handler, when you have no more data to send.

Best Wishes

[Mark]