Introductions are commands to perform a task in the microprocessor. The instructions consist of opcode and data called an operand. The operand may be the source only, destination only or both of them. Similarly, the destination can be a register, a memory location, or an output port. The various format of specifying the operands are called Addressing mode. The 8085 has five addressing modes.they are given below:
- Direct Addressing Mode
- Register Direct Addressing Mode
- Register Indirect Addressing mode
- Immediate Addressing Mode
- Implied/Implicit Addressing mode
Direct Addressing Mode:
The instructions using this mode specifies an effective address as a part of the introduction. The instruction size either 2-bytes or 3-bytes with first-byte op-code followed by 1 or 2 bytes of address of data.
E.g: LDA 9500H
This type of addressing is called absolute addressing.
Register Direct Addressing Mode
This mode specifies the register or register pair that contains the data.
E.g MOV A, B
Here, register B contains data rather than the address of the data. Other examples are ADD, XCHG, etc.
Register Indirect Addressing mode
In this mode, the address part of the instruction specifies the memory whose contents are the address of the operand. So in this type of addressing mode, it is the address of the address rather than address itself. (One operand is register)
E.g MOV R, M MOV M, R STAX,LDAX etc.
Immediate Addressing Mode
In this mode, the operand position is the immediate data. For 8-bit data, instruction size is 2 bytes and for 16-bit data, instruction size is 3 bytes.
E.g. MVI A, 32H
Implied/Implicit Addressing mode
The instructions of this mode do not have operands.
E.g. NOP: No operation
EI: Enable interrupt
DI: Disable interrupt
NEPAL4 days ago
First 4K Television in Nepal – Galaxy 4K by Ravi Lamichhane launched
How To6 days ago
Slow Internet? How to fix the issue of sluggish internet?
GADGETS6 days ago
Xiaomi Redmi 9 Power Price in Nepal With Specifications
android6 days ago
Android Vs iOS Which one to choose?
App4 days ago
How to Install Zoom on Linux?
Tech4 days ago
What is cyber army? Why cyber army is needed for a country?
How To3 days ago
How to use TOR browser?
News3 days ago
Dalay Dai! Who is Dalay Dai ? Learn detail (dalaydai.com)