Micro acronyms

is a general- purpose register that holds a part of the result from a multiplication or part of the dividend before a division.

RDX (data)

On the descriptor, it indicates the starting location of the memory segment.

Base address

This register is used for instructions such as multiplication, division, and some of the adjustment instructions.

RAX (accumulator)

indicate the condition of the microprocessor and control its operation.

RFLAGS

This segment holds code (programs and procedures) used by the microprocessor and defines the starting address of the section of memory holding code.

CS (code)

This flag bit activates if a word or doubleword is addressed on a non-word or non-doubleword boundary.

AC (alignment check)

addresses the next instruction in a section of memory defined as (instruction pointer) a code segment.

RIP (instruction pointer)

This segment is an additional data segment that is used by some of the string instructions to hold destination data.

ES (extra)

________ (destination index)- often addresses string destination data for the string instructions.

RDI

allows the microprocessor to address only the first 1M byte of memory space.

Real mode operation

register that often addresses source string data for the string instructions.

RSI (source index)

are supplemental segment registers available in the 80386- Core2 microprocessors to allow two additional memory segments for access by programs.

FS and GS segments

This segment is a section of memory that contains most data used by a program.

DS (data)

This flag indicates that the Pentium- Pentium 4 microprocessors support the CPUID instruction.

ID (identification)

This segment defines the area of memory used for the stack.

SS (stack)

This provides information about a virtual mode interrupt for the interrupt pending) Pentium- Pentium 4 microprocessors.

VIP (virtual interrupt pending)

addresses an area of memory called the stack.

RSP (stack pointer)

This is a copy of the interrupt flag bit available to the Pentium- Pentium 4 microprocessors.

VIF (virtual interrupt)

is the actual memory location accessed by a program.

Physical address

points to a memory location in all versions of the microprocessor for memory data transfers.

RBP (base pointer)

is the count of ones in a number expressed as even or odd.

P (parity)

Holds the carry after addition or the borrow after subtraction.

C (carry)

This register sometimes holds the offset address of a location in the memory system in all versions of the microprocessor.

RBX (index)

Is used in protected mode operation to select the privilege level for I /O devices.

IOPL (I /O privilege level)

This flag is used with debugging to control the resumption of execution after the next instruction.

RF (resume)

is a general- purpose register that also holds the count for various instructions.

RCX (count)

This flag occurs when signed numbers are added or subtracted.

O (overflow)

requests the access privilege level of a memory segment.

Requested Privilege Level (RPL)

The ________ provides the system with information about the Pentium microprocessor, such as its version number and manufacturer.

CPUID instruction

This flag indicates that the current task is nested within another task in protected mode operation.

NT (Nested Task)

invisible registers- registers that are not directly addressed by software.

Program

holds the arithmetic sign of the result after an arithmetic or logic instruction executes.

S (Sign)

The carry flag also indicates ________, as dictated by some programs and procedures.

error conditions

This flag selects either the increment or decrement mode for the DI and /or SI registers during string instructions.

D (direction)

other name of offset address.

Displacement

Shows that the result of an arithmetic or logic operation is zero.

Z (zero)

This flag bit selects virtual mode operation in a protected mode system.

VM (virtual mode)

locates the next instruction within the code segment.

Instruction pointer

This flag controls the operation of the INTR (interrupt request) input pin.

I (interrupt)

TTL

Transistor to Transistor Logic.

selects any location within the 64K byte memory segment.

Offset address

is any memory that stores information.

Cache

is defined as the address generated by a program.

Linear address

allows any physical memory location to be assigned to any linear address.

Memory paging mechanism

is one that can be placed into any area of memory and executed without change.

Relocatable program

Generate memory addresses when combined with other registers in the microprocessor.

SEGMENT REGISTERS

Descriptor zero where it must contain all zeros, and may not be used for accessing memory.

Null descriptor

defines the start of the code segment.

Code segment register

is used in protected mode operation to select the privilege level for I/O devices. If the ________ is lower than the current privilege level, an interrupt occurs, causing execution to suspend.

I/O privilege level (IOPL)

CISC

(Complex Instruction Set Computer)

RISC

(Reduced Instruction Set Computer)

EPIC

(Explicitly Parallel Instruction Computing)

ISA

(industry standard architecture)

EISA

(extended ISA)

EMS

(Extended Memory System)

VGA

Variable Graphics Array

VESA

Video Electronics Standards Association

USB

(universal serial bus)

AGP

(advanced graphics port)

SATA

(Serial A dvanced Technology Attachment)

ATA

Advanced Technology Attachment

DOS

(disk operating system)

CD-ROM memory

(Compact Disk Read-Only Memory)

DVD

(Digital Versatile Disk)

BIOS

Basic Input/Output System

MMX

Multimedia Extension

Digital Equipment Corporation

DEC

WYSIWYG

What You See Is What You Get

TTL

Transistor to Transistor Logic

RTL

Resistor-Transistor Logic

SIMD

Single Instruction Multiple Data

AMD

Advanced Micro Devices

ENIAC

(Electronic Numerical Integrator and Calculator)

FORTRAN

(FORmula TRANslator)

ALGOL

(ALGOrithmic Language)

COBOL

(COmputer Business Oriented Language)

RPG

(Report Program Generator

TPA

(transient program area),

XMS

(extended memory system)

MSDOS

(Microsoft disk operating system)

PCDOS

(personal computer disk operating system)

IORC

(I/O read control)

IOWC

(I/O write control)

MRDC

(memory read control)

MWTC

(memory write control)

ASCII

(American Standard Code for Information Interchange)

BCD

Binary-coded decimal

ALU

Arithmetic logic unit

VLSI

very large scale integration

SRAM

Static RAM

DRAM

Dynamic RAM

This register is used for instructions such as multiplication, division, and some of the adjustment instructions

RAX (accumulator)

This register sometimes holds the offset address of a location in the memory system in all versions of the microprocessor

RBX (index)

is a general-purpose register that also holds the count for various instructions

RCX (count)

is a general-purpose register that holds a part of the result from a multiplication or part of the dividend before a division

RDX (data)

points to a memory location in all versions of the microprocessor for memory data transfers

RBP (base pointer)

often addresses string destination data for the string instructions

RDI (destination index)

register that often addresses source string data for the string instructions

RSI (source index)

These registers are only found in the Pentium 4 and Core2 if 64-bit extensions are enabled

R8 through 15

stores data through this pointer and is explained later in the text with the instructions that address stack data

The stack memory