Mastering Assembly Programming

Direct addressing

Just as in the case of code addressing, this mode implies that the address of either the source or destination operand (depending on the instruction and intention) is explicitly specified. However, unlike code addressing, we are able to specify the address itself, except when loading it into a register first. Consider the example of loading the value of a variable into a register or storing it from register to memory:

 mov al, [name_of_variable] ; or mov [name_of_another_variable], eax

In both cases, name_of_variable and name_of_another_variable are translated by the assembler into the addresses of those variables. Of course, we may also use registers for this purpose. The following example illustrates an if…else clause: ...