Data copy/ Transfer Instruction | Instruction set of 8086 Microprocessor

In this article, I have discussed about different instruction sets of 8086 microprocessor and will discuss the instruction Data copy/ transfer instruction briefly.
Submitted by Uma Dasgupta, on March 22, 2019

8086 instructions are divided into following types:

Data copy/ Transfer Instruction
Arithmetic and logical instruction
Branch instruction
Loop instruction
Machine control instruction
Flag manipulation instruction
Shift and rotate instruction
String instruction

Data copy/ Transfer Instruction

1) MOV- Move

Transfers data from 1 register/memory to another register/memory. Direct loading of segment register with immediate data is not permitted.

Example:

    Mov     Ax,Bx
    Mov     Ax,1000x
    Mov     Ds,1000H
    Load    5000H
    Load    Ds with 5000H
    Mov     Ds,As

2) PUSH: Push to stack

This instruction pushes the content of specified register or memory location onto the stack. Stack pointer decremented by 2.

First- Higher byte

Second-Lower byte

3) POP: Pop from stack

This instruction when executed loads a specified register memory location with the contents of the memory location of which the address is formed using the current stack segment and stack pointer.

4) XCHG: Exchange

Exchanges the content of specified source and destination operand.

Note: Exchange of two memory location is not allowed.

5) IN: input code

This is used for reading an input code address of input code, may be specified either directly or indirectly.

AL (8 bit) & AX (16bit) are destination register.

Dx is the default register which is allowed to have implicit post register.

IN AL, O3H – reads data from 8bit port whose address is 03H.

6) OUT: Output to the port

It is used for writing output to the port. The address may be specified directly or indirectly data odd address is transfer from D18 – D15 even address code is transfer from D0-D7.

Example: