The assembler directives are the instructions to the assembler regarding the program being assembled. They are also called pseudo instructions or pseudo opcodes. The assembler directives are used to specify the start and end of a program, attach value to variables, allocate storage locations for input/output data, to define the start and end of segments, procedures, macros, etc. The assembler directives control the generation of machine code and the organization of the program. But no machine codes are generated for assembler directives. Some of the assembler directives that can be used for 8085 assembly language program development are listed below:
DB – Define Byte. Used to define byte type variable.
DW – Define word. Used to define a 16-bit variable.
END – Indicates the end of the program.
ENDM – End of the macro. Indicates the end of a macro sequence.
EQU – Equate. Used to equate numeric value or constant to a variable.
MACRO – Defines the name, parameters, and start of a macro.
ORG – Origin. Used to assign the starting address for a program.