Hi,
      The _A-CDS gives the offset of A from CDS.  It's used to add
the offset of _A onto the PC to get the correct place to return the
data.  Used in a routine to output  data to an lcd here  by the looks
of it.

Martin

> Hi to all,
>
> I see this example code in some body else's design and I
> do not clearly understand the meaning of   " movlw  _A-CDS "
> or movlw _B-CDS. Since _A, _B and CDS are labels what is the purpose of
> subtracting from
> each other . can some body explain more about this.
>
>
>
> CDS
> _A
>                  retlw H'80'
>                  dt "A"
>                  retlw 0
>
> _B
>                  retlw H'81'
>                  dt "B"
>                  retlw 0
>
>
>                 movlw    _A-CDS
>                 call            output
>
>
> Andre