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

Determine the basic machine language instructions, Determine the basic Mach...

Determine the basic Machine language instructions Machine language instructions and data are in terms of 0s and 1s and are stored in the memory. It isn't possible to distinguis

Explain the propagation delay characteristics for digital ic, Explain the ...

Explain the Propagation Delay characteristics for digital IC's. Ans: Propagation Delay: - The speed of a digital IC operation is given in terms of propagation delay ti

Classes, write a program to copt values of object without using copy constr...

write a program to copt values of object without using copy constructor or = operator

Advantages of specifying parameter assignment using defparam, State The adv...

State The advantages of specifying parameter assignments using defparam are: - This method always has precedence over specifying parameters at the instance of instantiation.

Can the size of an array be declared at runtime, Can the size of an array b...

Can the size of an array be declared at runtime?              No, the size of an array can't be declared at run time, we always require to mention the dimensions of an array at

Define busy waiting and spinlock, Define busy waiting and spinlock.  Wh...

Define busy waiting and spinlock.  When a process is in its critical section, any other process that tries to enter its critical section must loop continuously in the entry cod

What do you mean by interrupts, Q. What do you mean by Interrupts? The ...

Q. What do you mean by Interrupts? The term interrupt is an exceptional event which causes CPU to temporarily transfer its control from presently executing program to a separat

Two services that are used to deal with communication, Explain about the tw...

Explain about the two services that are used to deal with communication. Message Service: Used by the application servers to change short internal messages, all system commu

Strings made of left curly braces, In a logical system, a judgement is a st...

In a logical system, a judgement is a statement that is either true or false. So far, you are most familiar with the type of judgement "A is true", which is often simply abbreviate

Backpropagation learning routine, Backpropagation Learning Routine: Co...

Backpropagation Learning Routine: Conversely as with perceptrons there the information in the network is stored in the weights than the learning problem comes down to the ques

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