Hi,

I'm not having any luck with my attempts to write to the EEPROM data area
of my 16C84. Can anyone suggest where I'm going wrong...please.

I'm using the MPASM assembler and I get the following error message
when I try and use the Option, and EECON registers (repeats for every mention
of these registers)

Warning EEDATA.ASM 77 : Argument out of range: EECON1 (0088).
                        Least significant bits used.
Warning EEDATA.ASM 79 : Argument out of range: EECON2 (0089).
                        Least significant bits used.
Warning EEDATA.ASM 266 : Argument out of range: OPTION (0081).
                        Least significant bits used.


Heres the relevant section of my code:

; Target Chip           PIC16C84
; DATE                  27/10/1997
; ITERATION             1.0
; FILE SAVED AS         eedata.asm
; CLOCK                 Xtal 32.768KHz (4x30.5uS = 120uS  cycle)
; DESCRIPTION           expt with data EEPROM
;****************************************************************
List P=16C84

INTCON  EQU     00BH
GIE     EQU     7       ;part of intcon regr Global Interrupt Enable
EEIE    EQU     6       ;part of intcon regr
TOIE    EQU     5       ;part of intcon regr Timer0 Int Enable
INTE    EQU     4       ;part of intcon regr
RBIE    EQU     3       ;part of intcon regr
TOIF    EQU     2       ;part of intcon regr Timer0 Flag
INTF    EQU     1       ;part of intcon regr
RBIF    EQU     0       ;part of intcon regr
STATUS  EQU     003H
RP0     EQU     5       ;part of status regr Register bank select bit
OPTION  EQU     081H
TEMP    EQU     010H    ;storing a counter here
W       EQU     0       ; pointer TO W REGISTER
tempa   EQU     011H
EECON1  EQU     088H
EEIF    EQU     004H    ;4 bit of EECON1
WRERR   EQU     003H    ;3 bit of EECON1
WREN    EQU     002H    ;2 bit of EECON1
WR      EQU     001H    ;1 bit of EECON1
RD      EQU     000H    ;0 bit of EECON1
EECON2  EQU     089H
EEDATA  EQU     008H
EEADR   EQU     009H


; origin vector
        ORG     00H
        GOTO    INIT
;****** interrupt vector ****************************
        ORG     04H
        GOTO    LOOP

; subroutine declarations

; write to EEPROM data section, enter with addr to write to in EEADR
; and data to be written in EEDATA. Interrupts must be disabled
; before writing
EEWR
        BCF     INTCON,GIE      ;ensure interrupts disabled
        BSF     STATUS,RP0      ;bank 1
        BSF     EECON1,WREN     ;enable a write
        MOVLW   055H            ;required sequence
        MOVWF   EECON2          ;required sequence
        MOVLW   0AAH            ;required sequence
        MOVWF   EECON2          ;required sequence
        BSF     EECON1,WR       ;required sequence, begin write
WAYT    NOP
        BTFSC   EECON1,WR       ;see if write is finished
        GOTO    WAYT            ;wait until it is
        BCF     STATUS,RP0      ;bank0
        RETURN

; read data from EEPROM data section, enter with addr to read in EEADR
; exit with data that has been read in EEDATA
EERD
        BSF     STATUS,RP0      ;bank 1
        BSF     EECON1,RD
HOLT    BTFSC   EECON1,RD
        GOTO    HOLT            ;wait for read to complete
        BCF     STATUS,RP0      ;bank0
        RETURN

; ********** main program starts here ******************************
INIT
        CLRW
        MOVWF   TEMP
        MOVWF   EEDATA
        MOVWF   EEADR

        BSF     STATUS,RP0      ;5 bank 1
        BCF     OPTION,TOCS     ;5
        BCF     OPTION,PSA      ;3 assign prescaler to timer
        BCF     OPTION,PS2      ;2
        BCF     OPTION,PS1      ;1
        BCF     OPTION,PS0      ;0
        BCF     STATUS,RP0      ;5 bank 0 again

        BCF     INTCON,TOIE     ;5 1=enable
        BCF     INTCON,EEIE     ;6 0=disable
        BCF     INTCON,INTE     ;4 0=disable
        BCF     INTCON,RBIE     ;3 0=disable
        BCF     INTCON,GIE      ;7 1=enable unmasked interrupts

LOOP
        INCF    TEMP
; write, then read something to/from EEPROM data section
        movfw   TEMP
        movwf   EEDATA  ;write data thats same as value in TEMP
        ANDLW   03FH    ;0011 1111 clear top bits
        movwf   EEADR
        call    EEWR    ;to addr thats same as value in TEMP

        clrf    EEDATA  ;clear it to see if its really read

        call    EERD    ;read into EEDATA


; display the results here...

        GOTO    LOOP

; reset vector
        ORG     01FFH
        GOTO    INIT
        END
; *************************************************************

Really grateful for any suggestions.

Cheers
--
erik