3.10 __interrupt Keyword

The IAR __interrupt keyword specifies the qualified function is an interrupt handler. The interrupt vector is specified separately with a #pragma vector = number pragma that must precede the function.

Suggested Replacement

There is an MPLAB XC8 qualifier that performs a similar task to this keyword.

Use the MPLAB XC8 __interrupt qualifier with the required vector number as argument. The compiler provides predefined macros that represent the vector numbers, for example SPI_STC_vect_num.

Caveats

The Common C Interface must be enabled using -mext=cci to use the __interrupt qualifier.

Examples

Consider migrating IAR code such as:

volatile int x;
#pragma vector=2
void __interrupt incIsr(void) {
    x++;
}

to MPLAB XC8 code similar to:

#include <xc.h>
 
volatile int x;
void __interrupt(2) incIsr(void) {
    x++;
}

Further Information

See the Interrupts section in the MPLAB XC8 C Compiler User's Guide for AVR MCUs for more information on writing interrupt functions.