Introduction to Assembly Language Flashcards
Can improve the readability and clarity especially in assembly language where the purpose of a set of instructions is often ambiguous.
Comment
Is a part of a program that is ignored by the assembler.
Comment
What does a comment begin with?
semicolon (;)
These are words in which the assembler assigns a special meaning and it cannot be used as identifiers.
Reserved Words
Categories of Reserved Words
Instructions
Directives
Operators
Pre-defined Symbols
These are statements that will be translated into machine language and executed by the computer.
Instructions
Statements that give information to the assembler
Directives
Are sometimes called pseudo-ops
Directives
These are used at assembly time to affect the value of an operand
Operators
These are symbols that return information to your program.
Pre-defined Symbols
Is a user-defined name or variable that you apply in the program that is used as reference
Identifier
Types of Identifiers
Name
Label
It refers to the address of a data item
Name
It refers to the address of an instruction or procedure
Label
Two types of statements
Instructions
Directives
Consists of a set of statements
Statement
Maximum number of characters for a valid identifier
31 characters
Maximum number of characters for a title
60 characters
It tells the assembler to ignore all other request and to adopt the DOS segment sequence-stack, data and code
DOSSEG
It specifies and initializes the memory model before defining any segment
MODEL
What are the different memory models
Tiny, Small, Medium, Compact, Large
Memory Model with 0 number of data and code segments
Tiny
Memory Model with 1 data segment and 1 code segment
Small
Memory Model with 1 data segment and more than 1 code segments
Medium
Memory Model with more than 1 data segments and 1 code segment
Compact
Memory Model with more than 1 data segments and more than 1 code segments
Large
It defines the size of the stack
.STACK
Default stack size
1024 bytes
It defines and mark the beginning of data segment
.DATA
It defines and marks the code segment which consists of a set of instructions
.CODE
It is placed at the last line of the source code
END
Is used for descriptive data such as person’s name or simply a message
String
A string must end with a ____ symbol
Dollar ($)
They are used to define arithmetic values and memory addresses
Numeric Constant
