// PIC18 in C - Versione 0.1a - Luglio 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/pwm.htm

// Reference: PIC18F14K50 data sheet

#define _XTAL_FREQ 16000000 // Default PIC18F14K50 clock

#define PWM_T 199u // See text - 20 kHz @ Fclk = 16 MHz (199 = 200 - 1)
#define PWM_DC 320u  // See text - 40% => 320 / 200 / 4

#include "configurationsbits.h"

void main(void) {

    OSCCONbits.IRCF = 7; // Set internal clock to 16 MHz

    T2CONbits.T2OUTPS = 0; // Timer2 1:1 Postscaler
    T2CONbits.T2CKPS = 0; // Timer2 1:1 Prescaler
    PR2 = PWM_T; // Timer2 Period Register (last count)

    CCP1CONbits.CCP1M = 0b1100; //PWM mode; P1x active-high
    CCP1CONbits.P1M = 0b00; // Single output: P1x controlled by steering

    PSTRCONbits.STRSYNC = 1; // Output steering update occurs on next PWM period
    PSTRCONbits.STRA = 0; // P1A pin is assigned to port pin
    PSTRCONbits.STRB = 0; // P1B pin is assigned to port pin
    PSTRCONbits.STRC = 0; // P1C pin is assigned to port pin
    PSTRCONbits.STRD = 1; // P1D pin has the PWM waveform with polarity control from CCP1M<1:0>
    TRISCbits.RC2 = 0; // Set P1D (aka RC2) as output

    CCPR1L = PWM_DC >> 2; // Set PWM Ton - 8 MSB bits
    CCP1CONbits.DC1B = PWM_DC & 0x03; // Set PWM Ton - 2 LSB bits

    T2CONbits.TMR2ON = 1; // Timer2 on

    while (1);
}