Embedded C interrupt and while loop question

[hithesh123]

Basic question about while loop. It's common to use while loop for checking interrupt flag. Can I use while to check 2 interrupt flags -

while((!INT1F) & (!INT2F));

IAR gives me an error "Warning[Pa082]: undefined behavior: the order of volatile accesses is undefined in this ...."

Interrupt subroutine question -

let's say i am in a while loop waiting for interrupt flag - while(!INT1F);
This while loop is inside a function called ack().
But a time out interrupt occurs and I wanna get out of the function ack(). Is this possible?

 

[Jinzpaul4u]

Hello there,

Let me clarify one thing why are you using while loop for interrupt ?

The basic thing interrupt is a subroutine and most of the case its hardware control means through s/w only we can clear or read. When ever the interrupt occurs the hardware set interrupt flag bit ..so Our program execution would pause for a while to service the interrupt and it would continue .

. The processor responds by suspending its current activities, saving its state, and executing a small program called an interrupt handler (or interrupt service routine, ISR) to deal with the event. This interruption is temporary, and after the interrupt handler finishes, the processor resumes execution of the previous thread.

so just make ISR routine and code it.

Best regards.