Saturday, 5 May 2012

8085 addressing modes


Addressing modes define the way operands are specified in the instruction. In 8085 there are four addressing modes.
1.immediate addressing mode
2.register addressing mode
3.direct addressing mode
4.indirect addressing mode

immediate addressing mode:
in this operand is specified in the instruction it self.
Example: MVI A,55H

Register addressing mode:
in this addressing mode operand is stored in a register. And that register is specified in the instruction
Example: MOV C,A

direct addressing mode:
Operand is stored in the memory. The address of operand is specified in the instruction.
Example: IN 10H

indirect addressing mode:
Operand is stored in the memory. The address of operand is held in a register and the register is specified in the instruction.
Example: LXI H,1020H
MOV A,M ; indirect addressing mode
Here M points to(contains) address 1020H, At his address operand is stored. By executing this instruction, the content of 1020H is loaded into accumulator A

Back                                                  Contents                                           Next

No comments:

Post a Comment