>David:
>See my comments at ##### in the code.
>
>Been there done EXACTLY that  :-(
>
>David Duffy wrote:
> >
> > Tony wrote:
> > >David Duffy wrote:
> > > >          bsf     wren            ;enable eeprom writing
> > > >          movlw   h'55'           ;
> > > >          movwf   eecon2          ;eeprom write unlock sequence
> > > >          movlw   h'aa'           ;
> > > >          movwf   eecon2          ;eeprom write unlock sequence
> > > >          bsf     wr              ;initiate data eeprom write
> > > >          bcf     wren            ;disable the eeprom writing
> > >
> > >
> > >This last line probably kills the write routine.
> > >
> > >Try leaving WR set until the write is completed.
> >
> > I put the wrong version in my last email - corrected one is;
> >
> >
> ;******************************************************************************
> > ;* 'ee_write' writes one
> byte.                                                *
> > ;* enter with eeprom address in w and eeprom data in eedata (bank
> 2).         *
>
>##### Instead put the data in a tempory location. I will call
>##### it "EETemp"
>
>
> >
> ;******************************************************************************
>
>##### Make sure that your banks are correct. They sound wrong to me.
>
>
> > ee_write:                       ;
> >          bank2                   ;bank 2
> >          movwf   eeadr           ;set up eeprom address
>
>##### This store writes over the previous value that is being
>##### used to write to the EEPROM if two writes are done quickly.
>##### Storing the data ahead of the test for the EEPROM being
>##### ready will causes the same problem.
>
>
> >          bank0                   ;bank 0
> > ew_busy:                        ;
> >          btfsc   ee_busy         ;is the eeprom busy from a previous write?
> >          goto    ew_busy         ;yes, loop & wait
>
>##### Do the stores after the EEPROM is ready
>##### Set the bank
>#####      Bank2
>#####      movwf   eeadr           ;set up eeprom address
>##### Now Store the data
>#####      movf    EETemp,W
>#####      movwf   eedata
>
>
> >          bcf     gie             ;no, disable the global interupt
> >          bank3                   ;bank 3
> >          bcf     eepgd           ;make it a data eeprom write
> >          bsf     wren            ;enable eeprom writing
> >          movlw   h'55'           ;
> >          movwf   eecon2          ;eeprom write unlock sequence
> >          movlw   h'aa'           ;
> >          movwf   eecon2          ;eeprom write unlock sequence
> >          bsf     wr              ;initiate data eeprom write
> >          bank0                   ;bank 0
> >          bsf     ee_busy         ;set flag to say eeprom is busy
> >          bsf     gie             ;re-enable the global interupt
> >          return                  ;exit
> >
> > If I put a 12ms delay in just before the return it works ok.
> > I'm now clearing the WREN bit in the interrupt routine.
> > My flag (ee_busy) is also cleared in the same spot.