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

Determine no.of processes to avoid race condition, To avoid race condition,...

To avoid race condition, the maximum number of processes that may be simultaneously inside the critical section is The maximum number of processes is one to ignore race conditi

Chemistry, what are the applications of photochemistry?

what are the applications of photochemistry?

Er diagrams, how can I draw er diagram for sell & storage section of a drug...

how can I draw er diagram for sell & storage section of a drugstore?

Target_parent, TARGET = "_parent" "_parent" is used in a situation whe...

TARGET = "_parent" "_parent" is used in a situation where a frameset file is nested inside another frameset file. A link in one of the inner frameset documents that uses "_par

Explain the different fields of an instructions, Explain the significance o...

Explain the significance of different fields of an instruction An instruction is a command given to a computer to perform a particular operation on some given data and the form

Explain executing request using message-passing architecture, Explain the E...

Explain the Executing Requests Using a Message-Passing Architecture Executing requests using a message-passing architecture requires good fundamental client-server programming

Queueing process, explain in detail about queueing process

explain in detail about queueing process

Convergence mean with respect to e-commerce, What does the term convergence...

What does the term convergence mean with respect to E-commerce? Convergence with respect to e-commerce   The ability to leverage and integrate the several data sources and

Electrically erasable programmable rom - computer memory, Explain Electrica...

Explain Electrically Erasable Programmable ROM - Computer Memory? The next level of erasability is the EEPROM which able to be erased under software control. This is the most f

Explain in detail about the dynamic timing, Explain in detail about the Dyn...

Explain in detail about the Dynamic timing a. Design is simulated in full timing mode. b. Not all possibilities tested, as it is dependent on input test vectors. c. Simul

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