Explain direct addressing mode with example, Computer Engineering

Assignment Help:

Q. Explain Direct Addressing Mode with example?

Direct Addressing Mode

A direct operand signifies to contents of memory at an address referred by the name of the variable.

Mode

Description

Example

Direct

The direct operands are also calledas relocatable operands as they represent the offset of a label from the beginning of a segment. On reloading a program even in a different segment will not cause change in the offset that is why we call them relocatable. Please note that a variable is considered in Data segment (DS) and code label in code segment (SS) by default. Thus, in theexample, COUNT, bydefault will be assumed to be

in data segment, while LABEL 1, will be assumed to be in code segment. If we specify, as a direct operand then the address is non-relocatable. Please note the value of segment register will be known only at the run time.

MOV COUNT, CL 

; move CL to COUNT (a

; byte variable)

MOV AL,COUNT 

; move COUNT to AL

JMP LABEL1 

; jump to LABEL1

MOV AX,DS:5 

; segment register and 

; offset

MOV BX,CSEG:2Ch 

; segment name and offset

MOV AX,ES:COUNT 

; segment register and 

; Variable.

; The offsets of these 

; variables are calculated

; with respect to the 

; segment name (register)

; specified in the

; Instruction. 

 

 


Related Discussions:- Explain direct addressing mode with example

What is machine language, What is Machine Language? To write program fo...

What is Machine Language? To write program for a computer we need to specify, directly or indirectly the sequence of machine instructions.  These instructions  inside  computer

Explain dataflow computing, DATAFLOW COMPUTING A substitute to the Von ...

DATAFLOW COMPUTING A substitute to the Von Neumann model of calculation is dataflow computation model. In the dataflow model, control is tied to flow of data. Order of instruct

What is computer motherboard, If you open your computers case, the motherbo...

If you open your computers case, the motherboard is the flat, rectangular piece of circuit board to which the whole thing seems to connect to for one reason or one another. It'

Logic diagrams for same boolean expression, Q. Logic diagrams for same Bool...

Q. Logic diagrams for same Boolean expression? The expression F can be simplified using Boolean algebra. The logic diagram of simplified expression is drawn in fig (b)

Operations of the web, Operations of the Web mainly depend on hypertext as ...

Operations of the Web mainly depend on hypertext as its means of interacting with users. But what is hypertext? Hypertext as such is the same as regular text that is it can be read

System programming, concurrentisation and vectorisation of program

concurrentisation and vectorisation of program

Explain meaning of each field format of icmp header, Give the format of ICM...

Give the format of ICMP header and explain meaning of each field. The format of ICMP header is given below: Internetwork Control Message Protocol (ICMP) ICMP H

Pipe, Your shell should accept and execute the pipe "|"  operator. This wil...

Your shell should accept and execute the pipe "|"  operator. This will look like the following: | The functionality of this operator is to execute command1 and send i

Explain virtual packets, Explain Virtual Packets. The router can't tran...

Explain Virtual Packets. The router can't transfer a copy of a frame from one kind of network to other since the frame formats be different. More significantly, the router cann

Existential elimination, Existential Elimination : Now we have a sente...

Existential Elimination : Now we have a sentence, A, is with an  existentially quantified variable, v, so then just for every constant symbol k, that it does not appear anywhe

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd