Chapter 3 and 4 (โ๐ฃ๐บ ๐๐ฆ๐ง๐งโ) Flashcards
transfers a copy of a byte or word from the source addressing register or contents of a memory location to the destination register or memory location
Register Addressing
most common form of data addressing and, once the register names are learned, is the easiest to apply
Register Addressing
transfers the source, an immediate byte, word, addressing doubleword, or quadword of data, into the destination register or memory location
Immediate Addressing
data immediately follow the hexadecimal opcode in the memory
Immediate Addressing
directs the assembler to assemble the program into a single code segment.
.MODEL TINY
indicates the start of the code segment
.CODE
statement indicates the starting instruction in the program
.STARTUP
causes the program to exit to DOS.
.EXIT
indicates the end of the program file.
END
moves a byte or word between a memory location and a register
Direct Addressing
transfers data between a memory location, located within the data segment, and the AL (8-bit), AX (l6-bit), or EAX (32-bit) register
Direct Addressing
3 bytes wide
Direct Addressing
almost identical to direct addressing, except that the instruction is 4 bytes wide instead of 3
Displacement Addressing
inform the assembler where the data segment begins.
.DATA
allows one data segment and one code segment.
SMALL model
transfers a byte or word between a register and a memory location addressed by an index or base register
Register indirect addressing
allows data to be addressed at any memory location through an offset address held in any of the following registers: BP, BX, DI, and SI.
Register indirect addressing
transfers a byte or word between a register and the memory location addressed by a base register (BP or BX) plus an index register (DI or SI)
Base-plus-index addressing
moves a byte or word between a register and the memory location addressed by an index or base register plus a displacement
Register relative addressing
transfers a byte or word between a register and the memory location addressed by a base and an index register plus a displacement.
Base relative-plus-index addressing
The second register of a pair of registers is modified by the scale factor of to generate the operand memory address
Scaled-Index Addressing
is available only in the 80386 through the Pentium 4 microprocessor
Scaled-index Addressing
only available to the 64-bit extensions on the Pentium 4 or Core2
RIP relative addressing
allows access to any location in the memory system by adding a 32-bit displacement to the 64-bit contents of the 64-bit instruction pointer
RIP relative addressing
used to specify how information is stored in a memory array and can be quite useful with applications that use arrays
Data Structure
name of memory address
label
last-in, first-out
LIFO
data are placed onto stack using this
PUSH Instruction
data are removed
POP Instruction
Data Addressing Modes
- Register
- Immediate
- Direct
- Register Indirect
- Base plus-index
- Register relative
- Base relative-plus-index
Program Memory-addressing Modes
- Direct
- Relative
- Indirect addressing
Instruction that copies content of the source operand into the destination operand;
Source never changes
MOV
Specifies any 8-bit register or 16-bit register
Register Addressing
Instruction that transfers byte or word that immediately follows the opcode into the register or memory location
MOV Immediate
Relative to the instruction pointer
Relative
identify the start of a file and the type of memory model used with the file
.MODEL
Program exists in one segment, the code segment, and is assembled as a command (.COM) program
TINY
program uses a code and data segment and assembles as an execute (.EXE) program
SMALL
used to transfer data between EAX, AX, or AL and memory
direct addressing
3 bytes of memory
direct addressing
used with any register-memory transfer
displacement addressing
4 bytes of memory
displacement addressing
native binary code that the microprocessor understands and uses as its instructions to control its operation
Machine Language
selects the operation (addition, subtraction, move, and so on) that is performed by the microprocessor
Opcode
specifies the addressing mode (MOD) for the selected instruction
MOD Field
If the MOD field contains a 00, 01, or 10, the R/M field takes on a new meaning.
R/M Memory Addressing
occurs whenever memory data are referenced by only the displacement mode of addressing for 16-bit instructions
Special Addressing Mode
*found in the 80386 and above are obtained by either running these machines in the 32-bit instruction mode or in the 16-bit instruction mode by using the address-size prefix 67H
32-bit addressing Modes
If the contents of a segment register are moved by the MOV, PUSH, or POP instructions, a special set of register bits (REG field) selects the segment register
Segment MOV Instructions
REX
Register Extension
SIX FORMS OF PUSH AND POP
- Register
- Memory
- Immediate
- Segment register
- Flags
- All registers
Copies the contents of the internal register set, except the segment registers, to the stack.
PUSHA
PUSHA
Push all
Copies the contents of the flag register to the stack
PUSHF
PUSHF
Push Flags
PUSHAD
Push All Double
performs the inverse operation of a PUSH instruction
POP
removes data from the stack and places it into the target 16-bit register, segment register, or a 16-bit memory location
POP
POPF
Pop flags
removes a 16-bit number from the stack and places it into the flag register
POPF
POPFD
Pop flags double
removes a 32-bit number from the stack and places it into the extended flag register.
POPFD
removes 16 bytes of data from the stack and places them into the following registers, in the order shown: DI, SI, BP, SP, BX, DX, CX, and AX
POPA
POPA
Pop All
LEA
Load-effective address
loads a 16- or 32-bit register with the offset address of the data specified by the operand
LEA
LDS
Load data segment
LES
Load extra segment
LFS
Load pointer using FS
LGS
Load pointer using GS
LSS
Load pointer using SS
loads AL, AX, or EAX with data stored at the data segment offset address indexed by the SI register.
LODS
LODS
Load String Operand
STOS
Store String data
STOSB
Stores a byte
CMOV
Conditional move
REP
Repeat prefix
MOVS
Move string
- transfers data from one memory location to another
MOVS
- transfers a byte, word, or doubleword of data from an I/O device into the extra segment memory location addressed by the DI register
INS
INS
input string
OUTS
output string
- transfers a byte, word, or doubleword of data from the data segment memory location address by SI to an I/O device
OUTS
- exchanges the contents of a register with the contents of any other register or memory location
XCHG
XCHG
Exchange
- Load status flag into AH register
LAHF
LAHF
- Load All from Flags
SAHF
- Store all to flags
XLAT
- Translate
converts the contents of the AL register into a number stored in a memory table
XLAT
MOVSX
- move and sign-extend
MOVZX
- move and zero-extend
BSWAP
- byte swap
- takes the contents of any 32-bit register and swaps the first byte with the fourth, and the second with the third
BSWAP
CMOV
- conditional move
- class of instruction is new to the Pentium ProโCore2 instruction sets.
CMOV
- allows the programmer to deviate from the default segment
SEGMENT OVERRIDE PREFIX
- indicate how an operand or section of a program is to be processed by the assembler.
Directives
DB
- Define byte
DW
- Define word
DD
- Define doubleword
DQ
- Define quadword
DT
- Define ten bytes
EQU
- Equate directive
ORG
- Origin
- changes the starting offset address of the data in the data segment to location 300H
ORG
- tells the assembler what names have been chosen for the code, data, extra, and stack segments
ASSUME
PROC
- Procedure (?)
ENDP
End Procedure
MASM
- Microsoft Macro Assembler
ASM
- Assembler
TASM
- Turbo Assembler
