1
0
mirror of https://github.com/arduino/Arduino.git synced 2024-12-12 23:08:52 +01:00
Arduino/build/shared/lib/avrlib/spieeprom.c
2005-08-25 21:06:28 +00:00

92 lines
2.1 KiB
C
Executable File

/*! \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/signal.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;
}