Explain about two-pass assembler, Computer Engineering

Assignment Help:

Q. Explain about Two-pass assembler?

Assemblers usually make two or more passes through a source program in order to resolve forward references in a program. A forward reference is expressed as a type of instruction in code segment which is referencing the label of an instruction though the assembler hasn't yet encountered the definition of that instruction.

Pass 1:  Assembler reads the whole source program and creates a symbol table of labels and names used in the program that is name of data fields and programs labels and their relative location (offset) within the segment.

Pass 1 concludes the amount of code to be produced for every instruction. 

Pass 2:Assembler uses the symbol table which it constructed in Pass 1. Now it knows the relative position and length of every data field and instruction and it can complete object code for every instruction.  It generates .OBJ (Object file), .LST (list file) and cross reference (.CRF) files.


Related Discussions:- Explain about two-pass assembler

What is the difference among save and save as, Use SAVE when you are revisi...

Use SAVE when you are revising an existing document. Use SAVE AS when you are making a new document from scratch or an existing document. This will remain the original document

Determine the term queries-DBMS, Determine the term Queries-DBMS Querie...

Determine the term Queries-DBMS Queries most commonly allow information to be retrieved from tables. As the information is often spread across numerous tables, queries allow it

Determine the uses of defparam, Using defparam Parameter values can be ...

Using defparam Parameter values can be changed in any module instance in the design with keyword defparam. Hierarchical name of the module instance can be used to override para

Risc architecture - computer architecture, RISC  architecture - computer a...

RISC  architecture - computer architecture: What is reduced regarding it? The answer of this question is that to make all instructions the equal length the number of bits that

Different elements of a collaboration diagram, ? Object: The interaction am...

? Object: The interaction among objects takes place in a system. An object is depicted by a rectangle with the name of the object, preceded by a colon and underline. ? Relation

Credit line, The Credit Line The Credit Line is a set of informational f...

The Credit Line The Credit Line is a set of informational facts usually found below or beside a picture of a work of art. Should the picture appear in a book, magazine, poster,

What are assembly attributes, Attributes are declarative tags in code that ...

Attributes are declarative tags in code that put in additional metadata into an assembly.

Explain possible attacks on the wired equivalent privacy, Question : (a...

Question : (a) IEEE802.11 supports two types of network architecture, describe these architectures with the support of diagrams detailing the network components. (b) IEEE80

Explain process of file transfer protocol, Q. Explain process of File Trans...

Q. Explain process of File Transfer Protocol? FTP (File Transfer Protocol), a standard Internet protocol, is the simplest way to exchange files between computers on Internet. L

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

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