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

Public key infrastructure solutions, Public Key Infrastructure solutions ...

Public Key Infrastructure solutions The use of public-key based security systems requires great attention and due care in design and management of security features. The secur

Applications of generic framework for e-commerce executed, How are applicat...

How are applications of generic framework for e-commerce executed? To execute applications, this is essential to have Supporting Information and Organizational Infrastructure a

Example to show directory in doc, Q. Example to show directory in doc? ...

Q. Example to show directory in doc? Like a file name, the directory name may also have up to eight alpha-numeric characters. The directory name can also have an extension

Vector, Explain the characteristics of vector processing

Explain the characteristics of vector processing

Comparator, 6 bit magnitude comparator

6 bit magnitude comparator

What are advantages and disadvantages of using eeprom, What are advantages ...

What are advantages and disadvantages of using EEPROM? The benefits are that EEPROM do not have to be removed for erasure. Also it is possible to delete the cell contents selec

Explain conditions for the critical section problem solution, What are the ...

What are the properties which a data item should possess to implement a critical section? The Critical Section Problem Solution should satisfy the following conditions: 1.

What are superscalar processors, What are superscalar processors? Sever...

What are superscalar processors? Several instructions start implementation in the same clock cycle, and the processor is said to use multiple issue. Such processors are capable

What you mean by organizational effectiveness, Q. What you mean by organiza...

Q. What you mean by organizational effectiveness? Organizational effectiveness is measured in terms of productivity, structural flexibility, Employee involvement and Job satisf

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