4.2 Bare Metal Code

First, the Watchdog Timer has to be disabled and Low-Voltage Programming (LVP) has to be enabled using the following pragma code:

#pragma config WDTE = OFF   /* WDT operating mode->WDT Disabled */ 
#pragma config LVP = ON     /* Low voltage programming enabled, RE3 pin is MCLR */  

The following function initializes the system clock to have the HFINTOSC oscillator as input clock and to run at 1 MHz:

static void CLK_Initialize(void)
{ 
    OSCCON1 = 0x60;    /* set HFINTOSC as new oscillator source */
    OSCFRQ = 0x00;     /* set HFFRQ to 1 MHz */
}

The following function initializes the RC2 pin as output pin:

static void PORT_Initialize(void)
{
    TRISCbits.TRISC2 = 0;   /* configure RC2 as output */
}

The following function initializes Timer0 in 8-bit mode, sets the prescaler to 1:1, loads the TMR0H and TMR0L registers, clears the Interrupt flag and enables Timer0:

static void TMR0_Initialize(void)
{
    T0CON1 = 0x90;          /* select LFINTOSC and disable TMR0 sync*/
    TMR0H = 0x7B;           /* load TMR0H */
    TMR0L = 0x00;           /* load TMR0L */
    PIR0bits.TMR0IF = 0;    /* clear the interrupt flag */
    T0CON0 = 0x80;          /* enable TMR0 */
}

The following function configures the TMR0 output to RC2 in PPS:

static void PPS_Initialize(void)
{
    RC2PPS = 0x13;      /* configure RC2 for TMR0 output */
}

void main(void)
{
    CLK_Initialize();
    PORT_Initialize();
    TMR0_Initialize();
    PPS_Initialize();
    
    while(1)
    {
        ;
    }
}