// PIC18F14K50 in C - Versione 0.4 - Novembre 2010
// Copyright (c) 2010 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

// Internal Timer: Low Priority Interrupt

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


#pragma config FOSC = IRCCLKOUT  // Internal RC oscillator (F/4 to OSC2 - pin 3) 
#pragma config WDTEN = OFF       // Watchdog disabled
#pragma config LVP = OFF         // Disable Low Voltage Programming
#pragma config MCLRE = OFF       // Disable MCLR

void Low_Int (void);             // ISR function prototype

#pragma code low_vector = 0x18   // Setup interrupt vector

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

#pragma code                     // Back to normal code

#pragma interruptlow Low_Int
void Low_Int (void) 
{if (INTCONbits.TMR0IF == 1 )    // Interrupt from Timer0?
    {PORTC++;                    // Change LEDs status
     INTCONbits.TMR0IF = 0;      // Clear interrupt status
    }
}

void main (void)        // Program start here
{
 OSCCON = 0x70;         // Set internal clock to 16 MHz
 
 TRISC = 0x00;          // Set PORTC as Output 
 PORTC = 0x05;          // xxxx 0101 - Turn on some LEDs on port C
 ANSEL = 0;             // Set as Digital I/O
 ANSELH = 0;            // Set as Digital I/O

 RCONbits.IPEN = 1;     // Enable priority levels on interrupts
  
 OpenTimer0( TIMER_INT_ON & T0_16BIT & T0_SOURCE_INT & T0_EDGE_FALL & T0_PS_1_128 );
 INTCON2bits.TMR0IP = 0; // Set low priority interrupt
 
 INTCONbits.GIEL = 1;   // Enables all low priority interrupts
 INTCONbits.GIEH = 1;   // Enables all high priority interrupts (required even for LOW priority)

 while (1)  { }           
}