John Brown wrote:
>
> I am having trouble writing to the EEPROM in a on 16F873.
>
>
> Any suggestions greatly appreciated!
>


>         bsf     STATUS, RP0     ; select register bank 3
>         bcf     EECON1, EEPGD   ; Point to data memory
>         bsf     EECON1, WREN    ; Enable writes
> ;       bcf     INTCON, GIE     ; Only disable interrupts if already enabled_
> ;                               ;   otherwise discard
>         movlw   0x55            ; Write 55h to_
>         movwf   EECON2          ;   EECON2
>         movlw   0xAA            ; Write AAh to_
>         movwf   EECON2          ;   EECON2
>         bsf     EECON1, WR      ; Start write operation
> ;       bsf     INTCON, GIE     ; Only disable interrupts if already enabled_
> ;                               ;   otherwise discard
>         bcf     EECON1, WREN    ; Disable writes
>
>         goto LOOP


RAM bank select is still pointing to RAM page 3 before "goto LOOP"

You are writing to the EEPROM about 100 times per second which is
probably unnessary. Thats about 2 1/2 hours available time before the
location could end its life.

ROMzap initialises the PORT & TRIS registers from the boot code, so it's
not needed in your user code unless you need to specifically change
them.

--
Best regards

Tony

mICros
http://www.bubblesoftonline.com
mailto:sales@bubblesoftonline.com

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu