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

What is sector sparing, What is sector sparing? Low-level formatting al...

What is sector sparing? Low-level formatting also sets aside spare sectors not visible to the operating system. The controller can be told to change each bad sector logically w

Define the types of software life cycle, Define the types of software life ...

Define the types of software life cycle Any system progress refers to the initial part of the software life cycle: analysis, design, and implementation. During object oriented

What is functions indention, Use tabs to bring some structure into your fun...

Use tabs to bring some structure into your function body if(nPos > 1) then nRetrun = True else nRetrun = False end if

Signals and systems, Im doing computer engineering in Thailand.. Second yea...

Im doing computer engineering in Thailand.. Second year, and got project regarding sysnal and systems.. I and my team mates have no idea on what should we do.. Could u kindly sugge

C++, what is polymorphism

what is polymorphism

IT PMP project managemnet., Identify at least eight milestones for this pro...

Identify at least eight milestones for this project. Write a one-page paper describing each milestone using the SMART criteria?

Why is xml superior to other forms of data exchange, Why is XML superior to...

Why is XML superior to other forms of data exchange? The XML gives universal data format for integrated electronic business solutions. Other database systems and Relational dat

Nix commands, reate a directory "Unix" under your home directory. Command(...

reate a directory "Unix" under your home directory. Command(s): ………………………………………….

Real-time software, Real-Time Software Programs that monitor/analyze...

Real-Time Software Programs that monitor/analyze/ control real world events as they take place are known as real-time software. Elements of real-time software involve a data

Control signal, justify whether the control signal passes through same bus ...

justify whether the control signal passes through same bus as data ,address and instruction or not?

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