> Tanks for the reply's on this matter
> the thing is what i wand to do is more complicated
> I am reading 12 bit of data from an potentiometer when it is in the
> middle
> it should give something like 0x0800  "hex"
> when i turn left it decreases and when i turn right it increases
> The maximum increment should be no more than 0x3f  and the maximum
> decrement must not cross 0x40 within one reading if so i have to
> increment or decrement
> with these maximums or less until i reach the last readout.
>
> I hope i am more clear on what i want to do
>
> I can get the data msb first in the registers datahi and datalo but
> the LTC1286 allows also to read LSB first
>
> Example   first readout  could be  x0800  the next  0x0870
> the different is 70 positive is bigger than 0x3f so i add 0x3f to
> previous readout
> and compare again with the last readout witch can have changed in this
> example
> i assume not so 0x870 sub 0x83f is 0x31 witch is less than 0x3f  and the
> process stops
> until a new readout appears
>
> I don't understand what is the meaning msb stored at lower adress at the
> moment i am
> trying simulating this in MacPic
>
>   Storage1      equ   0x10
>   Storage2      equ   0x11
>   Storage3      equ   0x12
>   Storage4      equ   0x13
>   TmpReg1     equ   0x14
>   TmpReg2     equ   0x15
>   datahi           equ   0x16
>   datalo           equ   0x17
>
>    movlw         0x01         ;
>    movwf        datalo       ;
>    movwf        Storage1     ;
>    movlw         0x80         ;
>    movwf        datahi       ;
>    movwf        Storage2     ;
>    clrf             TmpReg1      ;
>    clrf             TmpReg2      ;
>
> start
>
>   ; movwf       Storage1
>   ; movwf       TmpReg1
>
>    movf            datahi,W
>    subwf          Storage2,W
>    movwf         TmpReg2
>    btfss             STATUS,Z
>    decf              TmpReg1,F
>    movf             datalo,W
>    subwf           TmpReg1,F
>   ; incf               datalo
>
>    goto              start
>
> As i already  sad    thanks  for all the reply's on this matter
>
> Marcel   Electronic  Workshop Scope
>
> Amsterdam .