SYMBOLS CHART
Every one of the parts on code line in assembler is known as token, for instance on the code line:
MOV AX, Var
We comprise three tokens, the MOV instruction, the AX operator, and the VAR operator. What the assembler does to produce the OBJ code is to read each one of the tokens and appear for it on an internal "equivalence" chart identified as the reserved words chart, which is where all the mnemonic meanings we use as instructions are establish.
Follow this process, the assembler reads MOV, seems for it on its chart and recognizes it as a processor instruction. similarly it reads AX and identifies it as a register of the processor, but when it seems for the Var token on the reserved words chart, it does not get it, so then it seems for it on the symbols chart which is a table where the names of the constants, variables and labels used in the program where their addresses on memory are incorporated and the sort of data it contains, are found.
at times the assembler comes on a token which is not distinct on the program, consequently what it does in these cased is to pass a second time by the source program to confirm all references to that symbol and put it on the symbols chart. There are symbols which the assembler will not find given that they do not belong to that segment and the program does not know in what part of the memory it will get that segment, and at this time the linker comes into action, which will make the structure necessary for the loader so that the segment and the token be distinct when the program is loaded and previous to it is executed.

Posted Date: 5/4/2012 4:17:36 AM | Location : United States

Ask an Expert

Related Discussions:- describe symbols chart in assembly process ?, Assignment Help, Ask Question on describe symbols chart in assembly process ?, Get Answer, Expert's Help, describe symbols chart in assembly process ? Discussions

Write discussion on describe symbols chart in assembly process ?
Your posts are moderated

Write your message here..

Related Questions

Problem - programming language, Problem - programming language: A Prob... Problem - programming language: A Problem is to carry out a particular task. For solving the problem, some input has to be given to the system. The system will process or mani

Designing computer based information systems-background, DESIGNING COMPUTER... DESIGNING COMPUTER BASED INFORMATION SYSTEMS Background The role of Management Information Systems (MIS) in an organization can be considered as providing

Microprocessor, what is computer? explaine the block diagram of a general p... what is computer? explaine the block diagram of a general purpose digital computer.

Computer organization, what is integrated memory circut what is integrated memory circut

Data base, advantages of file base system advantages of file base system

Data output, Data Output : Processed data is no use to you if you cannot u... Data Output : Processed data is no use to you if you cannot use it. Once data has been processed, you will either: (1) Send it as a data file to another system, e.g. write a fi

Operating system, what is operating system what is operating system

FEMAL. REPODUCATIVE. SYSTEM, Ask question #Minimum. Hello. ser can. y... Ask question #Minimum. Hello. ser can. you. tell. me. that. what. is. the. batter. side. for. BIOLOGY. Students. from. class. 12. / xii. 100 words accepted#

Processor, The role of array processor The role of array processor

Classification of computers, Classification of Computers DIGITAL, ANAL... Classification of Computers DIGITAL, ANALOG AND HYBRID Computers are of three basic types – Digital, Analog, and Hybrid. Current use of the word “computer” almost a