Chapter_3

Chapter_3 - MOVInstruction MOV destination,source MOV AX,BX...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
    MOV Instruction MOV destination,source MOV AX,BX MOV SUM,EAX MOV EDX,ARRAY[EBX][ESI] MOV CL,5 MOV DL,[BX]
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Addressing Modes These are the different ways in which data may be accessed by the microprocessor. Immediate. Register. Memory. Direct. Register indirect. Base plus index. Register relative. Base relative plus index. Scaled indexed.
Background image of page 2
    Immediate Directly accessible to the EU. The address is part of the instruction. Useful in initializations. MOV EAX,1111000B MOV CL, 0F1H
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Register Directly accessible to the EU. Most compact and fastest executing instructions. Operands are encoded in the instruction. MOV EBX,EDX MOV AL,CL
Background image of page 4
    Memory When reading or writing to memory the execution unit passes an offset value, the effective address, to the bus interface unit which then computes the physical address.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Direct [ ] { } { } [ ] { } operand 16 DS PA operand EA + × = = Simplest memory addressing mode. Direct addressing (3 bytes long). MOV EAX,DS:SUM MOV DS:[3000H],AL Displacement addressing (>3 bytes long): MOV DS:[500H],EDX MOV CX,COUNT+5
Background image of page 6
    Register Indirect ( 29 ( 29 ( 29 { } ( 29 ( 29 ( 29 + × = = ESI EDI EBX 16 DS PA ESI EDI EBX EA MOV EAX, DS:[EBX] MOV DS:[EDI],EDX
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Base Plus Index Similar to register indirect. The base registers, (BX, BP), and index registers, (DI, SI), are combined in pairs (base, index) to indirectly access data. Any two 32 bits registers, with the exception of the ESP
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 25

Chapter_3 - MOVInstruction MOV destination,source MOV AX,BX...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online