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

Fully parallel associative processor (fpap), Fully Parallel Associative Pro...

Fully Parallel Associative Processor (FPAP):  This processor accepts the bit parallel memory organisation. FPAP has two type of this associative processor named as: Word Org

Creating a function, I''m suppose to create a function called calc_rectang_...

I''m suppose to create a function called calc_rectang_area(height, width),that takes two parameters: the height and width of the rectangular and return the area of the rectangular.

Show list files by dir command, Q. Show list files by Dir command? The ...

Q. Show list files by Dir command? The Dir command can also be used to list files from the exacting directory. For example, the list of files present in the WORD directory in d

Explain language processing, System Software 1. Explain language proces...

System Software 1. Explain language processing? Explain its activities in detail. 2. Discuss briefly about Assembler directives. Also explain about Macro definition and call

Symmetric and asymmetric encryption algorithms, Compare and contrast symmet...

Compare and contrast symmetric & asymmetric encryption algorithms. Your response should contain a brief overview of the cryptographic basis for every type of algorithm, and a compa

Full adder, design a FULL adder with two half adders and an or gate

design a FULL adder with two half adders and an or gate

Grid computing, Grid Computing means applying the resources of a lot of com...

Grid Computing means applying the resources of a lot of computers in a network simultaneously to a one problem for solving a scientific or a technical problem that needs a large nu

Important part of process - canonical genetic algorithm, Important part of ...

Important part of Process - canonical genetic algorithm: In such a scenario evolution or random mutations are often highly deleterious or can say harmful to the organism it me

Interpreted language and a compiled language, Difference between an interpr...

Difference between an interpreted language and a compiled language? Ans) A compiled language is written and then run by a compiler which checks its syntax and compresses it int

Assembly Language, Write an assembly program to simulate a microwave

Write an assembly program to simulate a microwave

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