8085 Addressing Modes

Addressing Modes


The microprocessor has different ways of specifying the data for the instruction. These are called “addressing modes”.


The 8085 has Five addressing modes:


1)  Implied Addressing mode: In this type of addressing mode, No operand (register or data) is specified in the instruction. The operand is inherent to the instruction. 
    
Example:   CMA (Complement Accumulator) , SIM , RIM etc 
  
2)  Immediate Addressing Mode: In this type of addressing mode, immediate data byte is provided with the instruction. 


Example: MVI A  32H; 
         MVI B  AAH; 
etc. 


3)  Direct Addressing Mode: In this type of addressing mode, the 16bit memory address is directly provided with the instruction. 


Example:   LDA C500H ;
etc 


4)  Indirect Addressing Mode: In this type of addressing mode, the 16bit memory address is indirectly provided with the instruction using a register pair


Example:   LDAX  D;   
(Load the accumulator with the contents of the memory location whose address is stored in the register pair DE)

5)  Register Addressing mode:   This type of addressing mode specifies register or register pair that contains data. 


Example:   ADD B;  
           MOV B, A;