eeprom.c

Go to the documentation of this file.

/*
 * EEPROM access routine for Sensor Control
 * (c) 2007 by Matthias Arndt <marndt@asmsoftware.de>
 * Use at your own risk!
 */
#include "t89c51cc02.h"
#include "datatypes.h"
#include "eeprom.h"

unsigned char xdata* eepromptr;

BYTE EEPROM_read(BYTE address)
{
        BYTE c;
        

        eepromptr=(unsigned char xdata*) address;

        /* wait if EEPROM is still busy */
        EEPROM_wait();

        /* activate EEPROM */
        EECON |= MSK_EECON_EEE;

        /* read from EEPROM */
        c=*eepromptr;

        /* disable EEPROM */
        EECON &= ~MSK_EECON_EEE;
        
        return(c);
}

void EEPROM_write(BYTE d,BYTE address)
{
        eepromptr=(unsigned char xdata*) address;

        /* wait if EEPROM is still busy */
        EEPROM_wait();

        /* activate EEPROM */
        EECON |= MSK_EECON_EEE;

        /* write to EEPROM latch */
        *eepromptr=d;
        
        /* disable EEPROM */
        EECON &= ~MSK_EECON_EEE;
}

void EEPROM_flush()
{
        bit oldEA;
        /* wait if EEPROM is still busy */
        EEPROM_wait();
        oldEA=EA; EA=0; /* disable interrupts if needed */

        /* activate EEPROM write sequence - do not add any instructions between those two lines */
        EECON=0x50;
        EECON=0xA0;

        EA=oldEA;       /* restore interrupt status */
}

---