// PIC18F14K50 in C - Versione 0.6 - Febbraio 2012
// Copyright (c) 2010-2012 VincenzoV.net
// Creative Commons | Attribuzione-Condividi allo stesso modo 3.0 Unported.
// Creative Commons | Attribution-Share Alike 3.0 Unported
// https://www.vincenzov.net/tutorial/elettronica-di-base/PIC18F14K50

// Esternal High Priority Interrupt INT0

#include <p18f14k50.h>
#include <delays.h>

//#pragma config FOSC = IRCCLKOUT  // Internal RC oscillator (F/4 to OSC2 - pin 3) 
#pragma config FOSC = HS         // High speed crystal
#pragma config WDTEN = OFF       // Watchdog disabled
#pragma config LVP = OFF         // Disable Low Voltage Programming
#pragma config MCLRE = ON        // Enable MCLR - Required for debug... maybe

void High_Int (void);            // ISR function prototype

#pragma code high_vector = 0x08   // Setup interrupt vector

void interrupt (void) 
{ _asm GOTO High_Int _endasm }   // Jump to ISR function (in-line assembler)

#pragma code                     // Back to normal code

#pragma interrupt High_Int
void High_Int (void) 
{if (INTCONbits.INT0IF == 1)
    {PORTC+=2;                   // Increments LEDs status
     INTCONbits.INT0IF = 0;      // Clear interrupt status
    }
}

void main (void)          // Program start here
{TRISC = 0x01;            // xxxx 0001 - Set RC1-RC2-RC3 as Output, RC0 as input 
 PORTC = 0x00;            // xxxx 000x - Turn off LEDs on port C
 
 ANSEL = 0x00;            // Set as Digital I/O
  
 RCONbits.IPEN = 1;       // Enable priority levels on interrupts
 INTCON2bits.INTEDG0 = 1; // Interrupt on rising edge
 INTCONbits.INT0IE = 1;   // Enables INT0 interrupts
 INTCONbits.INT0IF = 0;   // Clear interrupt status to avoid automatic interrupt ad "boot time"
 INTCONbits.GIEH = 1;     // Enables all interrupts (required even for LOW priority)
 
 while (1);               // Never ending loop    
}