Problem Statement:- Design suitable data structures and implement pass-I of a two-pass assembler for pseudo-machine in Java using object oriented feature. Implementation should consist of a few instructions from each category and few assembler directives. You can download source code from this link.
Pass-1 of two-pass assembler implementation Reviewed by Vaibhav Kumbhar on January 14, Rating: 5. Anonymous 27 August at Subscribe to: Post Comments Atom. Submit an article. Featured post Most frequently asked interview Questions In this article, we will cover some of the interview questions asked in campus placement interviews.
Popular Posts. Git stats 18 commits. Failed to load latest commit information. View code. Two pass assembler using C What is an Assembler? What is a Single Pass Assembler? What is a Two-Pass assembler? Why do we need a Two-pass assembler? Algorithm Design. When an assembler divides its tasks in two passes, it is called a Two-pass assembler. Pass Defines symbols and literals and remembers them in symbolic table form and literal table form respectively.
Keep track of location counter. Process pseudo-operations. Pass Generate object code by converting symbolic op-code into corresponding numeric op-code. Generate data for literals and look for values of symbols. Algorithm Design In our design of a Two-pass assembler, we are interested in generating machine codes from a given set of assembly language codes. Tasks performed by the assembler in the two passes are: Pass 1 — Define symbols and literals. The length of machine instructions would be determined.
The track of location counter LC would be kept. Symbol values must be remembered until pass 2. Some pseudo-ops, if present in the card, would be processed.
The literals, if present in the card, would be remembered. Pass 2 — Generate object program The second pass reads the program again from the beginning. Translation includes the following operations: Read operation from the remembered symbol values.
Generate Instructions. Data for DS, DC and literals would be generated. Remaining pseudo-ops which remained unprocessed from pass 1 would be processed. Pass 1 Database Input source program. A Machine Operation Table for indicating the symbolic mnemonic for each instruction and its length. A Pseudo-Operation table for indicating the symbolic mnemonic for each pseudo-op in Pass 1. A Symbol Table to store label and its value.
A Literal Table to store literal and assigned location. A copy of input source file to be used in pass 2 can be stored as a File pointer.
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