If I read your message correctly, it looks as if you made the same
mistake I did when I first started using the '84s EEPROM. EEADR gets
modified every time you do a write (it works OK to increment it on read
though). All you need to do is increment a register and copy it to EEADR
before you do a write.


Frank Richterkessing
Experimental Methods Engineer
GE Appliances

FRANK.RICHTERKESSING@APPL.GE.COM



>----------
>From:  David BALDWIN[SMTP:db@SDM.BEL.ALCATEL.BE]
>Sent:  Monday, March 24, 1997 12:54AM
>To:    PICLIST@MITVMA.MIT.EDU
>Subject:       16C84 EEPROM writing
>
>Hi,
>
>
>        I had like to write and read from the EEPROM of the 16C84. I tried to
>write at 0x00, and it worked. I tried to do another write, next the
>first one, setting the WREN bit and then the WR bit, after modifying the
>EEADR and EEDATA files. I only got something writed on the second
>location! I took my first code back and decided to make a loop,
>incrementing the EEADR register and doing each time the whole thing:
>
>        clrf temp
>loop    set WREN bit
>        write 55h to EECON2
>        write AAh to EECON2
>        set WR bit
>        move temp --> EEADR
>        set WR bit
>        btfss temp,6
>        goto loop
>
>
>        The only location that has been writed is location 63! Can anybody
>help
>me? Or is there any code I can get to make this work? Thanks in advance.
>
>-david
>