// PIC18 in C - Versione 0.2 - Ottobre 2014
// Copyright (c) 2014, Vincenzo Villa
// Creative Commons | Attribuzione-Condividi allo stesso modo 3.0 Unported.
// Creative Commons | Attribution-Share Alike 3.0 Unported
// https://www.vincenzov.net/tutorial/PIC18/interrupt.htm

// Reference: PIC18F14K50 data sheet (note: page as DS41350C printed edition)

// [1] REGISTER 9-12: TRISC: PORTC TRI-STATE REGISTER - Page 90
// [2] REGISTER 7-10: RCON: RESET CONTROL REGISTER - Page 74
// [3] REGISTER 7-3: INTCON3: INTERRUPT CONTROL 3 REGISTER - Page 67
// [4] REGISTER 7-2: INTCON2: INTERRUPT CONTROL 2 REGISTER - Page 66
// [5] REGISTER 9-11: PORTC: PORTC REGISTER - Page 90
// [6] REGISTER 9-15: ANSEL: ANALOG SELECT REGISTER 1 - Page 94

#include "configurationsbits.h"

void interrupt __high_priority my_isr_h(void) {
    if (INTCON3bits.INT1F == 1) { // INT1 external interrupt occurred ? [3]
        PORTCbits.RC0 = 0; // Turn off RC0 pin [5]
        INTCON3bits.INT1F = 0; // Clear INT1 flag [3]
    }
//  if (XXX.flag == 1) { // XXX interrupt occurred ? NOT USED HERE
//      ...
//      XXX.flag = 0; // Clear XXX flag [3]
//    }
    return;
}


// Low priority interrupt - NOT USED HERE
// void interrupt __low_priority my_isr_l(void) {
//    if (...) {
//    ...
//    }
//    return;
// } 


void main(void) {

    TRISCbits.RC0 = 0; // Set RC0 pin as output [1]
    PORTCbits.RC0 = 1; // Turn on RC0 pin [5]

    TRISCbits.RC1 = 1; // Set RC1 pin as input [1]
    ANSELbits.ANS5 = 0; // Digital input buffer of RC1 is enabled [6]

    RCONbits.IPEN = 1; // Enable priority levels on interrupts [2]
    
    INTCON3bits.INT1IP = 1; // INT1 External Interrupt Priority set to High [3]
    INTCON2bits.INTEDG1 = 0; // INT1 on falling edge [4]
    INTCON3bits.INT1E = 1; // Enables the INT1 external interrupt [3]
    INTCON3bits.INT1F = 0; // Clear INT1 flag [3]

    INTCONbits.GIEL = 1; // Enables all low priority interrupts

    while (1); // Do nothing, forever
}