init.c

/*
 * 20190405.010
 * SD Card
 *
 * File: init.c
 * Processor: PIC12F1840
 * Author: wizlab.it
 */

#include "init.h"

/*==============================================================================
 * System initialization
 *============================================================================*/
void init(void) {
    /*
    * Init Oscillator: 32MHz
    *  - SPLLEN[7]: 1 (4x PLL enabled)
    *  - IRCF[6-3]: 1110 (8MHz/32MHz)
    *  - SCS[1-0]: 00 (Clock by FOSC [FOSC = INTOSC])
    */
    OSCCON = 0b11110000;
    OSCTUNE = 0x00;

    /*
    * Options Register
    * Timer0 initialized here
    *  - WPUEN[7]: 1 (Weak pull ups disabled)
    *  - INTEDG[6]: 1 (External INT PIN interrupt on rising edge)
    *  - TMR0CS[5]: 0 (Timer0 source clock from internal instruction cycle clock [FOSC/4])
    *  - TMR0SE[4]: 1 (Timer0 increment on high-to-low transaction on INT PIN)
    *  - PSA[3]: 0 (Prescaler assigned to Timer0)
    *  - PS[2-0]: 111 (Prescaler set to 256)
    */
    OPTION_REG = 0b11010111;

    /*
    * PORT A
    *  - RA[7-6]: 00 (Not implemented)
    *  - RA[5]: 0 (Output, Led 1)
    *  - RA[4]: 0 (Output, SPI CS)
    *  - RA[3]: 1 (Input, Unused)
    *  - RA[2]: 1 (Input, SPI SDI)
    *  - RA[1]: 0 (Output, SPI SCK Master Mode)
    *  - RA[0]: 0 (Output, SPI SDO)
    */
    TRISA = 0b00001100;
    ANSELA = 0b00000000;
    LATA = 0;

    /*
    * Interrupts
    * TMR0IE: 0 (Timer0 interrupt disabled)
    * PEIE: 1 (Peripheral interrupts disabled)
    * GIE: 1 (Global interrupts disabled)
    */
    TMR0IE = 0;
    PEIE = 0;
    GIE = 0;
}


/*==============================================================================
 * Interrupt Service Routine
 *============================================================================*/
void __interrupt() isr(void) {
}