Displacement mode, the operands offset (the effective address of Figure 11.2) is contained as part of the instruction as an 8-, 16-, orbit displacement. The displacement addressing mode is found on few machines because, as mentioned earlier, it leads to long instructions. In the case of the x, the displacement value can be as long as 32 bits, making fora byte instruction. Displacement addressing can be useful for referencing global variables. The remaining addressing modes are indirect, in the sense that the address portion of the instruction tells the processor whereto look to find the address.
Base mode specifies that one of the 8-, 16-, orbit registers contains the effective address. This is equivalent to what we have referred to as register indirect addressing.
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