4. MUL Instruction

• The MUL (unsigned multiply) instruction multiplies an 8-, 16-, or 32-bit operand by either AL, AX, or EAX.

• The instruction formats are:

      MUL reg8/mem8
      MUL reg16/mem16
      MUL reg32/mem32
  

• The single operand is the multiplier.

• Note that immediate operand is not allowed:

      mul 10 ; *** invalid instruction
  

• The following table shows the default multiplicand and product, depending on the size of the multiplier:

   

       multiplicand × multiplier = product