parrocchetto/firmware.X/src/spi1.c

// This file is part of parrocchetto.

// parrocchetto is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// parrocchetto is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with parrocchetto.  If not, see <http://www.gnu.org/licenses/>.

#include "spi1.h"
#include <xc.h>
#include <stdint.h>

void spi1_init(void)
{
    IFS0bits.SPI1IF = 0;              // Clear the Interrupt flag
    IEC0bits.SPI1IE = 0;              // Disable the interrupt
    SPI1CON1bits.DISSCK = 0;          // Internal serial clock is enabled
    SPI1CON1bits.DISSDO = 0;          // SDOx pin is controlled by the module
    SPI1CON1bits.MODE16 = 0;          // Communication is 8 bit
    SPI1CON1bits.MSTEN = 1;           // Master mode enabled
    SPI1CON1bits.SMP = 0;             // Input data is sampled at the middle of data output time
    SPI1CON1bits.CKE = 0;             // Serial output data changes on transition from
                                      // Idle clock state to active clock state
    SPI1CON1bits.CKP = 0;             // Idle state for clock is a low level; 
                                      // active state is a high level
    SPI1CON1bits.PPRE = 3;            // Primary clock prescale 1:1
    SPI1CON1bits.SPRE = 6;            // Secondary clock prescale 2:1
    
    // PPS
    RPINR20bits.SDI1R = 6; // SDI1: RP6
    RPOR3bits.RP7R = 9;    // ~SS1: RP7
    RPOR4bits.RP8R = 7;    // SDO1: RP8
    RPOR4bits.RP9R = 8;    // SCK1: RP9

    spi1_end();            // Put ~SS1 high

    SPI1STATbits.SPIEN = 1;
}

inline uint8_t spi1_write(uint8_t x)
{
    SPI1BUF = x;
    while(!SPI1STATbits.SPIRBF);
    //asm("nop");
    //asm("nop");
    //asm("nop");
    //asm("nop");
    return SPI1BUF;
}


inline void spi1_writebuf(const uint8_t* buf, uint16_t buf_size)
{
uint16_t i;

    for(i = 0; i < buf_size; ++i)
        spi1_write(buf[i]);
}

inline void spi1_readbuf(uint8_t* buf, uint16_t buf_size)
{
uint16_t i;

    for(i = 0; i < buf_size; ++i)
        buf[i] = spi1_read();
}