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 a multitape tm, What is a multitape TM?  A  multi-tape  Turing ...

What is a multitape TM?  A  multi-tape  Turing  machine  having  of  a  finite  control  with  k-tape  heads  and k-tapes each tape is infinite in both directions. On a one mov

Explain about decimal numbers, Q. Explain about Decimal Numbers? Deci...

Q. Explain about Decimal Numbers? Decimal number system has 10 digits signified by 0,1,2,3,4,5,6,7,8 and 9. Any decimal number can be signified as a string of these digits an

Define the heat transfer processes, Heat Transfer Coursework An interna...

Heat Transfer Coursework An internal combustion engine of a passenger car is operating at steady state conditions e.g. constant speed (r.p.m.) and load (torque), so the engine

Define parity generator, Define parity generator During transmission, a...

Define parity generator During transmission, at sending end the message is applied to a parity generator, where the needed bit is formed.

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

State about the object models, State about the Object models Object mo...

State about the Object models Object models are used for explaining the objects in the system and their connection with each other in the system. The dynamic model explains in

Explain chomsky classification of languages, Explain chomsky classification...

Explain chomsky classification of languages with suitable examples Ans: Any language is appropriate for communication provided the syntax & semantic of the language is termed t

Explain about open system, Q. Explain about Open System? The 'Open Syst...

Q. Explain about Open System? The 'Open System' is a system within its environment. It receives input from environment as well as provides output to environment.  Illustrati

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