CODEWITHSUNDEEP
picxc8
Maria Jose Medrano
Maria Jose Medrano

Reputation: 21

XC8 Interrupt Configuration

I am trying to write a timer interrupt for a pic16f887. I have checked on several websites and most of them recommend writing the interrupt subroutine as

void interrupt Name (void)

however my program says that by doing so I am conflicting my interrupt name with the Isr. main.c:42: error: (1375) multiple interrupt functions (_led and _isr) defined for device with only one interrupt vector

This is a sample of my code.

/******************************************************************************/
/* Files to Include                                                           */
/******************************************************************************/

#define _XTAL_FREQ 4000000

#include <xc.h>
#include <stdint.h>        /* For uint8_t definition */
#include <stdbool.h>       /* For true/false definition */
#include <htc.h>

#include "system.h"        /* System funct/params, like osc/peripheral config */
#include "user.h"          /* User funct/params, such as InitApp */
#include "pic16f887.h"
/******************************************************************************/
/* User Global Variable Declaration                                           */
/******************************************************************************/

/* i.e. uint8_t <variable_name>; */

/******************************************************************************/
/* Main Program                                                               */
/******************************************************************************/
// CONFIG1
#pragma config FOSC = INTRC_CLKOUT// Oscillator Selection bits (INTOSC oscillator: CLKOUT function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled and can be enabled by SWDTEN bit of the WDTCON register)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF      // RE3/MCLR pin function select bit (RE3/MCLR pin function is digital input, MCLR internally tied to VDD)
#pragma config CP = OFF         // Code Protection bit (Program memory code protection is disabled)
#pragma config CPD = OFF        // Data Code Protection bit (Data memory code protection is disabled)
#pragma config BOREN = ON       // Brown Out Reset Selection bits (BOR enabled)
#pragma config IESO = OFF       // Internal External Switchover bit (Internal/External Switchover mode is disabled)
#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enabled bit (Fail-Safe Clock Monitor is disabled)
#pragma config LVP = OFF        // Low Voltage Programming Enable bit (RB3 pin has digital I/O, HV on MCLR must be used for programming)

// CONFIG2
#pragma config BOR4V = BOR40V   // Brown-out Reset Selection bit (Brown-out Reset set to 4.0V)
#pragma config WRT = OFF        // Flash Program Memory Self Write Enable bits (Write protection off)

void interrupt led(void)


{
    PORTA = 0X00;`enter code here`

}


void main(void)
{  
   OSCCON = 0b01110000;

    TRISA = 0X00;
    ANSEL = 0X00;
    ANSELH = 0X00;

    while(1)
    {
        PORTA = 0X03;
        __delay_ms(1000);
        PORTA = 0X01;
        __delay_ms(1000);


    }

}

Upvotes: 2

Views: 4950

Answers (1)

Mike
Mike

Reputation: 4288

if you have xc8 2.0 and up your ISR should look like this:

#include <xc.h>

....
void __interrupt() ISR(void)    
{
...... // do Interrupt stuff
}

If your device supports interrupt priorities (e.g. PIC18), with each function use the low_priority or high_priority arguments to __interrupt(). e.g.

void __interrupt(high_priority) ISR(void)

Inside the ISR body, determine the source of the interrupt by checking the interrupt flag. And don't forget to clear the interrupt flag in the ISR.

Upvotes: 1

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