Assembly Language

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Assembly Language High-Level Language

• Skill Area 311 Part B

Materials Prepared by Dhimas Ruswanto, BMm
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Lecture Overview

• Assembly Code
• Assembler
• Format of Assembly Code
• Advantages Assembly Code
• Disadvantages Assembly Code
• High-Level Language
• Types of High-Level Languages
• Advantages Disadvantages High-Level Language

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Assembly codeorAssembly language
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What is an Assembly Code?

• Symbolic instruction what humans can understand
• Form of alphanumeric symbols known as mnemonic
  codes.
• Can have maximum up to 5 letter combination
• E.g.
• ADD for addition
• SUB for subtraction

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Why Assembly Code?

• Maps directly into machine language
• Designed for a family of microprocessors

MOV AX, BXADD AX, 5A INC BX JMP 100
01010011110 11010110110 10011101010 01010101010
Compile
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What is an Assembler?

• A program that converts assembly code into
  machine code
• Takes basic computer instructions and converts
  into a pattern of bits
• Most popular assemblers
• 1. MASM (Microsoft assembler program)
• 2. TASM (Borland turbo assembler program)

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What is an Assembler?
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Instruction Format of Assembler

• An assembly program consists of set of statements
• Format
• LABEL COMMENT are optional
• OPCODE OPERAND(s) are mandatory

LABEL OPCODE OPERAND (s) COMMENT
AGAIN ADD R3,R3,R2 It will contain the product
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Instruction Format of Assembler

• OPCODE the thing the instruction is to do
• OPERAND the thing it is supposed to do it to
• LABEL a symbolic name which used to identify
  memory locations that are referred to explicitly
  in the program
• COMMENT message intended only for human

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Working

• Programmer write a program using a sequence of
  assemble instructions.
• This sequence of assembler instructions, known as
  the source code/source program, then specified to
  the assembler program when that program is
  started.
• It translates a source code into machine
  language.
• The output of the assembler program is called the
  object code or object program.

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Assembler Instruction Sample
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Advantages of Assembly Code

• It is easier to understand and use as compared to
  machine language.
• It is easy to locate and correct errors.
• It is modified easily

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Disadvantages of Assembly Code

• Machine dependent
• Since it is machine dependent therefore
  programmer should have knowledge of the hardware
  also

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High-level language
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What is High-Level Language?

• High-Level language is basically symbolic
  languages that use English words and/or
  mathematical symbols rather than mnemonic codes.
• Each instruction in the high-level language is
  translated into many machine language
  instructions.

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Purpose of High-Level Language

• To enable people (programmer) to write program
  easily and in their own native language
  environment (English).
• Examples
• C, C, Java, VB, HTML

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Types of High-Level Languages

• Languages have been developed for general purpose
  and specific purpose
• Types of High-Level Languages
• Algebraic Formula-Type Processing
• Business Data Processing
• String and List Processing
• Object Oriented Programming Language (OOP)
• Visual Programming Language

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Algebraic Formula-Type Processing

• Oriented towards the computational procedures for
  solving mathematical and statistical problem.
• Examples
• BASIC (Beginners All Purpose Symbolic
  Instruction Code)
• FORTRAN (Formula Translation)
• PL/I (Programming Language, Version 1)
• ALGOL (Algorithmic Language)
• APL (A Programming Language)

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Business Data Processing

• Emphasize their capabilities for maintaining data
  processing procedures and files handling
  problems.
• Examples
• COBOL (Common Business Oriented Language)
• RPG (Report Program Generator)

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String and List Processing

• Used for string manipulation including search for
  patterns, inserting and deleting characters.
• Examples
• LISP (List Processing)
• Prolog (Program in Logic)

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Object Oriented Programming Language

• In OOP, the computer program is divided into
  objects.
• Examples
• C
• Java
• HTML5

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Visual Programming Language

• Designed for building Windows-based applications.
• Examples
• Visual Basic
• Visual C

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Instruction Format

• Simple English
• printf(My name is Dhimas Ruswanto)
• Algebraic Format
• a2, b3
• sumab
• sum23
• sum5

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Advantages of High-Level Language

• User-friendly
• Similar to English with vocabulary of words and
  symbols
• Easier to learn
• Less time to write
• Easier to maintain
• Problem oriented rather than machine based
• Can run on any computer for which there exists an
  appropriate translator

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Disadvantages of High-Level Language

• Need to be translated into the machine language
  by a translator, thus a price in computer time is
  paid.
• The object code generated by a translator might
  be inefficient Compared to an equivalent assembly
  language program.

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Summary

• Assembly Code symbolic instruction that humans
  can understand
• Assembly Code
• LABEL OPCODE OPERANDS COMMENTS
• Assembler A program that converts assembly code
  into machine code
• High-Level language is basically symbolic
  languages that use English words and/or
  mathematical symbols rather than mnemonic codes.
• Types of High-Level Languages
• Algebraic Formula-Type Processing
• Business Data Processing
• String and List Processing
• Object Oriented Programming Language (OOP)
• Visual Programming Language