CWD              Convert Word to Doubleword          Flags: not altered
 
CWD
 
          Logic:    if (AX < 8000h) then
                        DX  0
                    else
                        DX  FFFFh
 
    CWD extends the sign bit of the AX register into the DX register. This
    instruction generates the double-word equivalent of the signed number
    in the AX register.
 
  --------------------------------------------------------------------------
   Operands                  Clocks   Transfers  Bytes   Example
   no operands                 5          -        1     CWD
  --------------------------------------------------------------------------
 
       Note:          This instruction will set DX to 0FFFFh if the sign
                      bit (bit 15) of AX is set; if bit 15 of AX is not
                      set, DX will be set to 0.

Seealso:


 CBW 
 DIV 
 IDIV