Assembly Language Help (alang.hlp) (Table of Contents; Topic list)
CBW/CWD Instruction
 ◄Summary► ◄Key► ◄Example►                    ◄Up► ◄Contents► ◄Index► ◄Back►
────────────────────────────────────────────────────────────────────────────
 
 10011000*
─────────────────┬─────────────────────────┬────────────────────────────────
 CBW             │ cbw                     │ 88/86 2
                 │                         │   286 2
                 │                         │   386 3
                 │                         │   486 3
─────────────────┼─────────────────────────┼────────────────────────────────
 CWDE            │ cwde                    │ 88/86 ──
                 │                         │   286 ──
                 │                         │   386 3
                 │                         │   486 3
─────────────────┴─────────────────────────┴────────────────────────────────
 
 10011001*
─────────────────┬─────────────────────────┬────────────────────────────────
 CWD             │ cwd                     │ 88/86 5
                 │                         │   286 2
                 │                         │   386 2
                 │                         │   486 3
─────────────────┼─────────────────────────┼────────────────────────────────
 CDQ             │ cdq                     │ 88/86 ──
                 │                         │   286 ──
                 │                         │   386 2
                 │                         │   486 3
─────────────────┴─────────────────────────┴────────────────────────────────
  * CBW and CWDE have the same encoding, and CWD and CDQ have the
    same encoding. The only difference is that in 32-bit mode CBW and
    CWD are preceded by the operand-size byte (66h), but CWDE and CDQ
    are not.
 
    In 16-bit mode, CWDE and CDQ are preceded by the operand-size byte,
    but CBW and CWD are not.
                                    -♦-