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Assembly Language – Lab 1Introduction, Program structure, comments, define variables

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Assembly Language• Assembly language makes it possible to write Machine Language

code.• A program called the Assembler does the translation.• Each line of a program is one of the following:

• an instruction• an assembler directive (or pseudo-op)• a comment

• Whitespace (between symbols) and case are ignored.• Comments (beginning with “;”) are also ignored.

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Program Structure

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Comments

• Anything after a semicolon is a comment.

Comment

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Defining Variables

• Defining variables goes under the .DATA segment

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Defining Variables

Name Type Value

Declaration syntax:

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Identifiers

• May consist of letters, digits, and the special characters

• ? . @ _ $ % (Thus, embedded blanks are not allowed).

• Names may not begin with a digit.

• If a dot is used, it must be the first character.

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Questions

• Can we use the following names as identifiers in assembly language:

#ASMadd

*NO

QUS%%$

_USE

PASS 1234%

CS221

Hi_

!Set1ONE

Learn@

Sign&

%Percent

@Data

YES

YES

YES

YES

NONO NO

NO

NO

NO

NO

YES

YES

NO

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EMU8086How to use the required software

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EMU8086 – How to use it

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EMU8086 – Open empty workspace

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EMU8086 – Press emulate, after coding

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EMU8086 – Press run to execute the code