* Data register operands
*
    xdef Start, Stop, End

Start:
    move.b #-1, d0    * Move byte size operand 
    move.w #-1, d1    * Move word size operand 
    move.l #-1, d2    * Move long word size operand 

    move.b d2, d3   * Move data register -> data register
    move.w d2, d4   * Move data register -> data register
    move.l d2, d5   * Move data register -> data register

    move.l #-1, d7
    add.b  #1,  d7

    move.l #-1, d7
    add.w  #1,  d7

    move.l #-1, d7
    add.l  #1,  d7

    nop

Stop:
End:
    end

Use:
break Start
disp/x $d7
disp/x $d6
disp/x $d5
disp/x $d4
disp/x $d3
disp/x $d2
disp/x $d1
disp/x $d0
disp/i $pc