spi.c

/*! \file spi.c \brief SPI Interface Driver for LPC2100. */
//*****************************************************************************
//
// File Name    : 'spi.c'
// Title        : SPI Interface Driver for LPC2100
// Author       : Pascal Stang - Copyright (C) 2004
// Created      : 2004.05.05
// Revised      : 2004.07.12
// Version      : 0.1
// Target MCU   : ARM processors
// Editor Tabs  : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested.  Nonetheless, you can expect most functions to work.
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

#include "lpc2000.h"
#include "global.h"
#include "spi.h"

void spiInit(void)
{
    // setup SCK pin P04
    PINSEL0 &= ~(3<<8);
    PINSEL0 |= 1<<8;
    // setup MISO pin P05
    PINSEL0 &= ~(3<<10);
    PINSEL0 |= 1<<10;
    // setup MOSI pin P06
    PINSEL0 &= ~(3<<12);
    PINSEL0 |= 1<<12;
    // setup SSEL pin P07
    PINSEL0 &= ~(3<<14);
    PINSEL0 |= 1<<14;

    // set maximum SPI rate
    S0SPCCR = 8;
    // set master mode, clock polarity and phase
    S0SPCR = (1<<SPCR_MSTR);
}

void spiSetClockDiv(u08 clockdiv)
{
    S0SPCCR = clockdiv;
}

void spiSendByte(u08 data)
{
    // wait until SPI bus is free
    while(!(S0SPSR & (1<<SPSR_SPIF)));
    // write SPI data
    S0SPDR = data;
}

u08 spiTransferByte(u08 data)
{
    // write SPI data
    S0SPDR = data;
    // wait until SPI transfer completes
    while(!(S0SPSR & (1<<SPSR_SPIF)));
    // return received data
    return S0SPDR;
}

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