eepromw.c

ICCAVR中所有的库函数源码

/* Modified by Richard Man
 */
/*
**	Purpose:    EEPROM read & write routines
**
**  Version:    1.0.0, 8:th of May 1999
**
**  Author:     Lars Wictorsson
**              LAWICEL / SWEDEN
**              http://www.lawicel.com   [e-mail]
**
**  History:    1999-05-08  Created
**/

/* These routines work for all AVR devices except for 2313 and below
 * The "location" argument is not bound so in theory you should call it
 * with something like
 *
 * #include <io????.h>
 *
 * ...
 * EEPROMwrite(addr & E2END, byte);
 */

#ifdef _M169
#include <iom169v.h>
#else
#include <io8515.h>	// ALL devices have the same EEPROM reg locations
#endif

#include <eeprom.h>

int EEPROMwrite( int location, unsigned char byte)
{
	unsigned char oldSREG;

    while (EECR & 0x02);                // Wait until any earlier write is done

	EEAR = location;

    EEDR = byte;

	oldSREG = SREG;
	SREG &= ~0x80;		// disable interrupt

    EECR |= 0x04;                       // Set MASTER WRITE enable
    EECR |= 0x02;                       // Set WRITE strobe

	SREG = oldSREG;
    return 0;                           // return Success.
                                        // Could be expanded so that
                                        // the routine checks that the address
                                        // is within the range of the chip.
}