Module 3.3: Assembly Language Addressing Modes and Instructions

Vocabulary flashcards covering basic operands, assembly addressing modes, the MOV instruction, and data type specifiers.

Destination Operand

The first operand in a two-operand assembly instruction, which contains data in a register or memory location.

Source Operand

The second operand in a two-operand assembly instruction, containing either the data to be delivered or the address of the data in a register or memory.

Register Addressing

An addressing mode in which a register contains the operand, providing the fastest data processing because it does not involve memory.

Immediate Addressing

An addressing mode in which the second operand is an immediate constant or expression, and the first operand defines the length of the data.

Direct Memory Addressing

An addressing mode requiring direct access to main memory, where one operand refers to a memory location and the other operand references a register.

Effective Address

The offset value that, combined with the segment start address (typically in the DS register), locates the exact position of data in memory.

Symbol Table

A table maintained by the assembler that stores the calculated offset values of all variables used in a program.

Direct-Offset Addressing

An addressing mode that uses arithmetic operators to modify an address in order to access specific elements in memory tables or variables.

Indirect Memory Addressing

An addressing mode utilizing base registers (EBX, EBP, BX, BP) or index registers (DI, SI) inside square brackets to reference memory locations, commonly used for arrays.

MOV Instruction

An instruction used to transfer data from one storage space to another, taking two operands of the same size while leaving the source operand unchanged.

Type Specifier

A keyword used to resolve size ambiguity in assembly instructions by explicitly stating the number of bytes being addressed in memory operations.

BYTE

A type specifier that addresses 1 byte of memory.

WORD

A type specifier that addresses 2 bytes of memory.

DWORD

A type specifier that addresses 4 bytes of memory.

QWORD

A type specifier that addresses 8 bytes of memory.

TBYTE

A type specifier that addresses 10 bytes of memory.