What is assembler, Computer Engineering

Assignment Help:

Q. What is Assembler?

An assembly program is used to transfer assembly language mnemonics to binary code for every instruction after the complete program has been written with support of an editor it's then assembled with help of an assembler. 

An assembler works in 2 stageswhich are: it reads your source code 2 times.  In first pass the assembler gathers all the symbols defined in the program accompanied by their offsets in symbol table.  On the 2ndpass through the source program it generates binary code for every instruction of the program and give all symbols an offset with respect to segment from symbol table.

The assembler produces three files. Object file, list file and cross reference file. The object file comprises the binary code for every instruction in program. It is created only when your program has been successfully assembled without errors.  Errors which are detected by assembler are known as the symbol errors.  For illustrationMOVE AX1, ZX1.

In the statement it reads the word MOVE and it attempts to match with mnemonic sets as there is no mnemonic with this spelling then it presumes it to be an identifier and searches for its entry in symbol table.  It doesn't even find it there hence gives an error as undeclared identifier.

List file is optional and comprises the source code, binary equivalent of every instruction and offsets of symbols in the program.  This file is for purelydocumentation purposes. A number of the assemblers available on PC are TURBO,MASM etc.


Related Discussions:- What is assembler

Time slice, The Linux Process Scheduler uses time slice to prevent a single...

The Linux Process Scheduler uses time slice to prevent a single process from using the CPU for too long. A time slice specifies how long the process can use the CPU. In our simulat

Explain about the object identity of object oriented, Explain about the Obj...

Explain about the Object Identity of object oriented analysis Object identity is a feature of an object that differentiates the objects from all other objects in the applicati

What is a client in sap terminology, What is a client in SAP terminology? ...

What is a client in SAP terminology? A S/W component that uses the service (offered by a s/w component) is known as a Client.  At the similar time these clients may also be ser

m-files and the power point presentation, Power point presentation Arra...

Power point presentation Arrange a 20 minutes power point presentation showing the original and processed filters.  Discuss the methods used for processing and comment on each r

What are the data types of the external layer, What are the Data types of t...

What are the Data types of the external layer? The Data types of the external layer are :- ACCP, Char, CLNT, CUKY, CURR, DATS, DESC, FLTP, INT1, INT2, INT4, LANG, LCHR, L

What is linq, It sets for Language Integrated Query. LINQ is collection of ...

It sets for Language Integrated Query. LINQ is collection of standard query operators that gives the query facilities into .NET framework language like C# , VB.NET.

How to create a bugzilla account? , 1. Enter your "E-mail address...

1. Enter your "E-mail address" and "Real Name" (or whatever name you need to call yourself) in the spaces given, then select the "Create Account" button. 2. Within moments, you

Explain the working of a 1-to-16 Demultiplexer, Using a suitable logic diag...

Using a suitable logic diagram explain the working of a 1-to-16 de multiplexer. Ans. 1-to-16 Demultiplexer Working: A demultiplexer obtains in data from one line and directs this

Explain the effect of cell breathing, Problem : (a) State and describe ...

Problem : (a) State and describe the transmission ranges associated with wireless transmission. Illustrate your answer with a diagram. (b) Sketch a graph representing how a

Define bandwidth, Define Bandwidth? When transferring blocks of data, i...

Define Bandwidth? When transferring blocks of data, it is of interest to know how much time is required to transfer an entire block, as blocks can be variable in size it is use

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