spieeprom.c

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/*! \file spieeprom.c \brief Interface for standard SPI EEPROM memories. */
//*****************************************************************************
//
// File Name    : 'spieeprom.c'
// Title        : Interface for standard SPI EEPROM memories
// Author       : Pascal Stang - Copyright (C) 2004
// Created      : 2004.10.07
// Revised      : 2004.10.07
// Version      : 0.1
// Target MCU   : Atmel AVR series
// Editor Tabs  : 4
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

#include <avr/io.h>
#include <avr/interrupt.h>

#include "spi.h"
#include "spieeprom.h"

// functions
void spieepromInit(void)
{
    // although there is no code here
    // don't forget to initialize the SPI interface itself
//  sbi(DDRB, 0);
}

u08 spieepromReadByte(u32 memAddr)
{
    u08 data;
//  cbi(PORTB,0);
    // send command
    spiTransferByte(SPIEEPROM_CMD_READ);
    // send address
    spiTransferByte(memAddr>>8);
    spiTransferByte(memAddr&0x00FF);
    // read contents of memory address
    data = spiTransferByte(0xFF);
    // return data
    return data;
//  sbi(PORTB,0);
}

void spieepromWriteByte(u32 memAddr, u08 data)
{
    // wait for any previous write to complete
    while(spieepromReadStatus() & SPIEEPROM_STATUS_WIP);

//  cbi(PORTB,0);
    // send command
    spiTransferByte(SPIEEPROM_CMD_WRITE);
    // send address
    spiTransferByte(memAddr>>8);
    spiTransferByte(memAddr&0x00FF);
    // send data to be written
    spiTransferByte(data);
//  sbi(PORTB,0);
}

void spieepromWriteEnable(void)
{
//  cbi(PORTB,0);
    // send command
    spiTransferByte(SPIEEPROM_CMD_WREN);
//  sbi(PORTB,0);
}

void spieepromWriteDisable(void)
{
//  cbi(PORTB,0);
    // send command
    spiTransferByte(SPIEEPROM_CMD_WRDI);
//  sbi(PORTB,0);
}

u08 spieepromReadStatus(void)
{
    u08 status;
//  cbi(PORTB,0);
    // send command
    spiTransferByte(SPIEEPROM_CMD_RDSR);
    // get status register value
    status = spiTransferByte(0xFF);
//  sbi(PORTB,0);
    return status;
}

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