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

How can we decrement and increment operations, How can we decrement and in...

How can we decrement and increment  operations We  can  implement decrement  and increment  operations  by  using  a  combinational circuit  or  binary  down/up counters.  In

Explain about olap, OLAP is called as online analytical processing which gi...

OLAP is called as online analytical processing which gives answers to queries which are multi dimensional in nature. It composes relational reporting and data mining for giving sol

Online movie booking system using data structures, I want to know...if ther...

I want to know...if there is a program available in C code using data structure for online movie booking system

Vugen recording and scripting, LoadRunner script code acquired from recordi...

LoadRunner script code acquired from recording in the ANSI C language syntax, shown by icons in icon view until you click Script View.

Eme, state function and path function

state function and path function

Methods for organising the associative memory, There are two methods for or...

There are two methods for organising the associative memory based on bit slices: Bit parallel organisation: In this organisation every bit slices which are not masked off,

Nmknl''knl, Ask question bhjjnjnnjnjm#Minimum 100 words accepted#

Ask question bhjjnjnnjnjm#Minimum 100 words accepted#

Explain the working of a binary counter, In binary counter the flip flop of...

In binary counter the flip flop of lowest order position is complemented with each pulse. This means that JK input position must be maintained with logic one

Illustrate the disadvantages of wireless technology, Disadvantages of wirel...

Disadvantages of wireless technology -  Range can be very limited -  Possible interference from nearby electronic devices -  Security issues (i.e. tapping illegally into

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