q salient features of direct addressing modea

Question

Q. Salient features of direct addressing mode?

A number of salient points about this technique are:

• This scheme offers a limited address space since if address field has n bits then memory space would comprise 2ⁿ memory words or locations. I.e. for illustration machine of Figure above direct addresses memory space will be 2¹⁰.

 • The effective address in this technique is described as address of operand which is,

EA  <-- A     and    (EA in the above illustration will be 500)

D = (EA)      (D in the above illustration will be 7) 

The second statement implies that the data is stored in memory location specified by effective address.

• In this addressing technique only one memory reference is needed to fetch the operand.