17. Immediate Operands

• An immediate operand is a constant value or the result of a constant expression.

• The assembler encodes immediate values into the instruction at assembly time.

• Here are some typical examples showing immediate operands:

          mov     cx, 20          ; Load constant to register
          add     var, 1Fh        ; Add hex constant to variable
          sub     bx, 25 * 80     ; Subtract constant expression
  

• Immediate data is never permitted in the destination operand.

• If the source operand is immediate, the destination operand must be either a register or direct memory to provide a place to store the result of the operation.

• Immediate expressions often involve the useful OFFSET operator.