Hi Neil,

Note that I added BANKSEL directives to your code.
I'll leave it up to you to see which ones could be removed because of
redundancy.
I may have made some boo-boos, so double-check things carefully.
Like I said before, you can add code to this routine to see if interrupts
were enabled or not.
Then based on this boolean condition, you can conditional enable or leave
interrupts disabled upon exit.

You might also want to investigate the state of WRERR upon power-up.
Have you checked all errata notes on the PIC16F627?
Just for kicks, you also might want to check the WR bit to ensure it is
getting cleared after a write completes.

Also (depending upon the situation) it is good practice to point the EEPROM
address register to another unused location upon exit as one of several
measures to help prevent corruption of the EEPROM location you just wrote.






;-----------------------------------------------------------------
; Write data to EEPROM (location supplied in W, data in E_DATA)
;-----------------------------------------------------------------

WriteEEData:
        BANKSEL PIR1
        bcf     PIR1,EEIF       ; Reset write-complete flag

        BANKSEL EEADR
        movwf   EEADR

        BANKSEL E_DATA
        movf    E_DATA,W        ; Get data to be stored

        BANKSEL PIR1
        bcf     PIR1,EEIF       ; Ensure interrupt flag off while in bank 0

        BANKSEL EEDATA
        movwf   EEDATA

      ; Previous BANKSEL also takes care of the following registers

        bsf     EECON1,WREN     ; Enable writes
        bcf     INTCON,GIE      ; Disable interrupts
        movlw   H'55'           ; Special seq
        movwf   EECON2          ; ...
        movlw   H'AA'           ; ...
        movwf   EECON2          ; ...
        bsf     EECON1,WR       ; Start write operation
        bcf     EECON1,WREN     ; Disable writes

        bsf     INTCON,GIE      ; Re-enable interrupts

        BANKSEL PIR1

WriteEEWait:
        btfss   PIR1,EEIF       ; Check EEIF flag for write completion
        goto    WriteEEWait

WriteEEDataDone:
        return



Hope this helps more than it hurts. :)


Best regards,

Ken Pergola

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body