SlideShare a Scribd company logo
ADDRESSING MODES OF 8086
1) Immediate addressing mode
2) Register addressing mode
3) Direct memory addressing mode
4) Register based indirect addressing mode
5) Register relative addressing mode
6) Base indexed addressing mode
7) Relative based indexed addressing mode
8) Implied addressing mode
1) Immediate addressing mode-
• In this mode, the operand is specified in the
instruction itself. Instructions are longer but
the operands are easily identified.
• Example:
• MVI CL, 12H
• This instruction moves 12 immediately into CL
register. CL ← 12H
2) Register addressing mode-
• In this mode, operands are specified using
registers. This addressing mode is normally
preferred because the instructions are compact
and fastest executing of all instruction forms.
• Registers may be used as source operands,
destination operands or both.
• Example:
• MOV AX, BX
• This instruction copies the contents of BX register
into AX register. AX ← BX
3) Direct memory addressing mode
• In this mode, address of the operand is directly specified in
the instruction. Here only the offset address is specified,
the segment being indicated by the instruction.
• Example:
• MOV CL, [4321H]
• This instruction moves data from location 4321H in the
data segment into CL.
• The physical address is calculated as
• DS * 10H + 4321
• Assume DS = 5000H
• ∴PA = 50000 + 4321 = 54321H
• ∴CL ← [54321H]
4) Register based indirect addressing
mode
• In this mode, the effective address of the memory may be
taken directly from one of the base register or index
register specified by instruction. If register is SI, DI and BX
then DS is by default segment register.
• If BP is used, then SS is by default segment register.
• Example:
• MOV CX, [BX]
• This instruction moves a word from the address pointed by
BX and BX + 1 in data segment into CL and CH respectively.
• CL ← DS: [BX] and CH ← DS: [BX + 1]
• Physical address can be calculated as DS * 10H + BX.
5) Register relative addressing mode-
• In this mode, the operand address is calculated
using one of the base registers and an 8 bit or a
16 bit displacement.
• Example:
• MOV CL, [BX + 04H]
• This instruction moves a byte from the address
pointed by BX + 4 in data segment to CL.
• CL ← DS: [BX + 04H]
• Physical address can be calculated as DS * 10H +
BX + 4H.
6) Base indexed addressing mode-
• Here, operand address is calculated as base
register plus an index register.
• Example:
• MOV CL, [BX + SI]
• This instruction moves a byte from the address
pointed by BX + SI in data segment to CL.
• CL ← DS: [BX + SI]
• Physical address can be calculated as DS * 10H +
BX + SI.
7) Relative based indexed addressing
mode
• In this mode, the address of the operand is
calculated as the sum of base register, index
register and 8 bit or 16 bit displacement.
• Example:
• MOV CL, [BX + DI + 20]
• This instruction moves a byte from the address
pointed by BX + DI + 20H in data segment to CL.
• CL ← DS: [BX + DI + 20H]
• Physical address can be calculated as DS * 10H +
BX + DI + 20H.
8) Implied addressing mode
• In this mode, the operands are implied and
are hence not specified in the instruction.
• Example:
• STC
• This sets the carry flag.

More Related Content

What's hot

Instruction sets of 8086
Instruction sets of 8086Instruction sets of 8086
Instruction sets of 8086
Mahalakshmiv11
 
Architecture of 8085 microprocessor
Architecture of 8085 microprocessorArchitecture of 8085 microprocessor
Architecture of 8085 microprocessor
AMAN SRIVASTAVA
 
System bus timing 8086
System bus timing 8086System bus timing 8086
System bus timing 8086
mpsrekha83
 
INTEL 80386 MICROPROCESSOR
INTEL  80386  MICROPROCESSORINTEL  80386  MICROPROCESSOR
INTEL 80386 MICROPROCESSOR
Annies Minu
 
Addressing modes of 8086
Addressing modes of 8086Addressing modes of 8086
Addressing modes of 8086
Dr. AISHWARYA N
 
Interfacing memory with 8086 microprocessor
Interfacing memory with 8086 microprocessorInterfacing memory with 8086 microprocessor
Interfacing memory with 8086 microprocessor
Vikas Gupta
 
Architecture of 8051
Architecture of 8051Architecture of 8051
Architecture of 8051
hello_priti
 
Instruction formats-in-8086
Instruction formats-in-8086Instruction formats-in-8086
Instruction formats-in-8086
MNM Jain Engineering College
 
Arm instruction set
Arm instruction setArm instruction set
Arm instruction set
Mathivanan Natarajan
 
8251 USART
8251 USART8251 USART
8251 USART
coolsdhanesh
 
Instruction format
Instruction formatInstruction format
Instruction format
Sanjeev Patel
 
8086 modes
8086 modes8086 modes
8086 modes
PDFSHARE
 
Addressing modes of 8051
Addressing modes of 8051Addressing modes of 8051
Addressing modes of 8051
SARITHA REDDY
 
Memory & I/O interfacing
Memory & I/O  interfacingMemory & I/O  interfacing
Memory & I/O interfacing
deval patel
 
Counters & time delay
Counters & time delayCounters & time delay
Counters & time delay
Hemant Chetwani
 
8051 Microcontroller PPT's By Er. Swapnil Kaware
8051 Microcontroller PPT's By Er. Swapnil Kaware8051 Microcontroller PPT's By Er. Swapnil Kaware
8051 Microcontroller PPT's By Er. Swapnil KawareProf. Swapnil V. Kaware
 
8086 microprocessor-architecture
8086 microprocessor-architecture8086 microprocessor-architecture
8086 microprocessor-architecture
prasadpawaskar
 
Interfacing with peripherals: analog to digital converters and digital to ana...
Interfacing with peripherals: analog to digital converters and digital to ana...Interfacing with peripherals: analog to digital converters and digital to ana...
Interfacing with peripherals: analog to digital converters and digital to ana...
NimeshSingh27
 
8257 DMA Controller
8257 DMA Controller8257 DMA Controller
8257 DMA Controller
ShivamSood22
 
Presentation on 8086 microprocessor
Presentation on 8086 microprocessorPresentation on 8086 microprocessor
Presentation on 8086 microprocessor
Diponkor Bala
 

What's hot (20)

Instruction sets of 8086
Instruction sets of 8086Instruction sets of 8086
Instruction sets of 8086
 
Architecture of 8085 microprocessor
Architecture of 8085 microprocessorArchitecture of 8085 microprocessor
Architecture of 8085 microprocessor
 
System bus timing 8086
System bus timing 8086System bus timing 8086
System bus timing 8086
 
INTEL 80386 MICROPROCESSOR
INTEL  80386  MICROPROCESSORINTEL  80386  MICROPROCESSOR
INTEL 80386 MICROPROCESSOR
 
Addressing modes of 8086
Addressing modes of 8086Addressing modes of 8086
Addressing modes of 8086
 
Interfacing memory with 8086 microprocessor
Interfacing memory with 8086 microprocessorInterfacing memory with 8086 microprocessor
Interfacing memory with 8086 microprocessor
 
Architecture of 8051
Architecture of 8051Architecture of 8051
Architecture of 8051
 
Instruction formats-in-8086
Instruction formats-in-8086Instruction formats-in-8086
Instruction formats-in-8086
 
Arm instruction set
Arm instruction setArm instruction set
Arm instruction set
 
8251 USART
8251 USART8251 USART
8251 USART
 
Instruction format
Instruction formatInstruction format
Instruction format
 
8086 modes
8086 modes8086 modes
8086 modes
 
Addressing modes of 8051
Addressing modes of 8051Addressing modes of 8051
Addressing modes of 8051
 
Memory & I/O interfacing
Memory & I/O  interfacingMemory & I/O  interfacing
Memory & I/O interfacing
 
Counters & time delay
Counters & time delayCounters & time delay
Counters & time delay
 
8051 Microcontroller PPT's By Er. Swapnil Kaware
8051 Microcontroller PPT's By Er. Swapnil Kaware8051 Microcontroller PPT's By Er. Swapnil Kaware
8051 Microcontroller PPT's By Er. Swapnil Kaware
 
8086 microprocessor-architecture
8086 microprocessor-architecture8086 microprocessor-architecture
8086 microprocessor-architecture
 
Interfacing with peripherals: analog to digital converters and digital to ana...
Interfacing with peripherals: analog to digital converters and digital to ana...Interfacing with peripherals: analog to digital converters and digital to ana...
Interfacing with peripherals: analog to digital converters and digital to ana...
 
8257 DMA Controller
8257 DMA Controller8257 DMA Controller
8257 DMA Controller
 
Presentation on 8086 microprocessor
Presentation on 8086 microprocessorPresentation on 8086 microprocessor
Presentation on 8086 microprocessor
 

Similar to Addressing modes of 8086

Addressing mode of 80286 microprocessor
Addressing mode of 80286 microprocessorAddressing mode of 80286 microprocessor
Addressing mode of 80286 microprocessor
pal bhumit
 
All-addressing-modes of the 80386 /microprocessor.pptx
All-addressing-modes of the 80386 /microprocessor.pptxAll-addressing-modes of the 80386 /microprocessor.pptx
All-addressing-modes of the 80386 /microprocessor.pptx
VidyaAshokNemade
 
8086 instruction set (with simulator)
8086 instruction set (with simulator)8086 instruction set (with simulator)
8086 instruction set (with simulator)
Aswini Dharmaraj
 
8086 Instruction set
8086 Instruction set8086 Instruction set
8086 Instruction set
karthiga selvaraju
 
Lecture 11
Lecture 11Lecture 11
Lecture 11
talhashahid40
 
Chapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMING
Chapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMINGChapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMING
Chapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMING
Frankie Jones
 
Adressing modes of 8086
Adressing modes of 8086Adressing modes of 8086
Adressing modes of 8086
KANNANKR12
 
8086 add mod
8086 add mod8086 add mod
8086 add mod
Mohansonale1
 
Chap3 8086 logical
Chap3 8086 logicalChap3 8086 logical
Chap3 8086 logical
HarshitParkar6677
 
Chapter3 8086inst logical 2
Chapter3 8086inst logical 2Chapter3 8086inst logical 2
Chapter3 8086inst logical 2
HarshitParkar6677
 
Notes 8086 instruction format
Notes 8086 instruction formatNotes 8086 instruction format
Notes 8086 instruction format
HarshitParkar6677
 
8086addressingmodes-200319141110.pdf
8086addressingmodes-200319141110.pdf8086addressingmodes-200319141110.pdf
8086addressingmodes-200319141110.pdf
TanmoyMondal89
 
8086 addressing modes
8086 addressing modes8086 addressing modes
8086 addressing modes
HarshitParkar6677
 
Addressing modes
Addressing modesAddressing modes
Addressing modes
rajukarki1599
 
addressing-modes-of-8086-mr-binu-joy-2 (2).pptx
addressing-modes-of-8086-mr-binu-joy-2 (2).pptxaddressing-modes-of-8086-mr-binu-joy-2 (2).pptx
addressing-modes-of-8086-mr-binu-joy-2 (2).pptx
Dr.MUTHURAJ BOSE
 
Addressing modes of 8086
Addressing modes of 8086Addressing modes of 8086
Addressing modes of 8086
HarshitParkar6677
 
Copy of 8086inst logical
Copy of 8086inst logicalCopy of 8086inst logical
Copy of 8086inst logical
HarshitParkar6677
 
Copy of 8086inst logical
Copy of 8086inst logicalCopy of 8086inst logical
Copy of 8086inst logical
HarshitParkar6677
 
Addressing Modes Of 8086
Addressing Modes Of 8086Addressing Modes Of 8086
Addressing Modes Of 8086
Ikhlas Rahman
 

Similar to Addressing modes of 8086 (20)

Addressing mode of 80286 microprocessor
Addressing mode of 80286 microprocessorAddressing mode of 80286 microprocessor
Addressing mode of 80286 microprocessor
 
All-addressing-modes of the 80386 /microprocessor.pptx
All-addressing-modes of the 80386 /microprocessor.pptxAll-addressing-modes of the 80386 /microprocessor.pptx
All-addressing-modes of the 80386 /microprocessor.pptx
 
8086 instruction set (with simulator)
8086 instruction set (with simulator)8086 instruction set (with simulator)
8086 instruction set (with simulator)
 
8086 Instruction set
8086 Instruction set8086 Instruction set
8086 Instruction set
 
Lecture 11
Lecture 11Lecture 11
Lecture 11
 
Chapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMING
Chapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMINGChapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMING
Chapter 3 INSTRUCTION SET AND ASSEMBLY LANGUAGE PROGRAMMING
 
Adressing modes of 8086
Adressing modes of 8086Adressing modes of 8086
Adressing modes of 8086
 
8086 add mod
8086 add mod8086 add mod
8086 add mod
 
Chap3 8086 logical
Chap3 8086 logicalChap3 8086 logical
Chap3 8086 logical
 
Chapter3 8086inst logical 2
Chapter3 8086inst logical 2Chapter3 8086inst logical 2
Chapter3 8086inst logical 2
 
Notes 8086 instruction format
Notes 8086 instruction formatNotes 8086 instruction format
Notes 8086 instruction format
 
1327 addressingmodesof8086-100523023240-phpapp02
1327 addressingmodesof8086-100523023240-phpapp021327 addressingmodesof8086-100523023240-phpapp02
1327 addressingmodesof8086-100523023240-phpapp02
 
8086addressingmodes-200319141110.pdf
8086addressingmodes-200319141110.pdf8086addressingmodes-200319141110.pdf
8086addressingmodes-200319141110.pdf
 
8086 addressing modes
8086 addressing modes8086 addressing modes
8086 addressing modes
 
Addressing modes
Addressing modesAddressing modes
Addressing modes
 
addressing-modes-of-8086-mr-binu-joy-2 (2).pptx
addressing-modes-of-8086-mr-binu-joy-2 (2).pptxaddressing-modes-of-8086-mr-binu-joy-2 (2).pptx
addressing-modes-of-8086-mr-binu-joy-2 (2).pptx
 
Addressing modes of 8086
Addressing modes of 8086Addressing modes of 8086
Addressing modes of 8086
 
Copy of 8086inst logical
Copy of 8086inst logicalCopy of 8086inst logical
Copy of 8086inst logical
 
Copy of 8086inst logical
Copy of 8086inst logicalCopy of 8086inst logical
Copy of 8086inst logical
 
Addressing Modes Of 8086
Addressing Modes Of 8086Addressing Modes Of 8086
Addressing Modes Of 8086
 

Recently uploaded

Railway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdfRailway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdf
TeeVichai
 
LIGA(E)11111111111111111111111111111111111111111.ppt
LIGA(E)11111111111111111111111111111111111111111.pptLIGA(E)11111111111111111111111111111111111111111.ppt
LIGA(E)11111111111111111111111111111111111111111.ppt
ssuser9bd3ba
 
Forklift Classes Overview by Intella Parts
Forklift Classes Overview by Intella PartsForklift Classes Overview by Intella Parts
Forklift Classes Overview by Intella Parts
Intella Parts
 
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
AJAYKUMARPUND1
 
Halogenation process of chemical process industries
Halogenation process of chemical process industriesHalogenation process of chemical process industries
Halogenation process of chemical process industries
MuhammadTufail242431
 
Immunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary AttacksImmunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary Attacks
gerogepatton
 
DESIGN A COTTON SEED SEPARATION MACHINE.docx
DESIGN A COTTON SEED SEPARATION MACHINE.docxDESIGN A COTTON SEED SEPARATION MACHINE.docx
DESIGN A COTTON SEED SEPARATION MACHINE.docx
FluxPrime1
 
The Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdfThe Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdf
Pipe Restoration Solutions
 
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
Dr.Costas Sachpazis
 
J.Yang, ICLR 2024, MLILAB, KAIST AI.pdf
J.Yang,  ICLR 2024, MLILAB, KAIST AI.pdfJ.Yang,  ICLR 2024, MLILAB, KAIST AI.pdf
J.Yang, ICLR 2024, MLILAB, KAIST AI.pdf
MLILAB
 
ASME IX(9) 2007 Full Version .pdf
ASME IX(9)  2007 Full Version       .pdfASME IX(9)  2007 Full Version       .pdf
ASME IX(9) 2007 Full Version .pdf
AhmedHussein950959
 
road safety engineering r s e unit 3.pdf
road safety engineering  r s e unit 3.pdfroad safety engineering  r s e unit 3.pdf
road safety engineering r s e unit 3.pdf
VENKATESHvenky89705
 
MCQ Soil mechanics questions (Soil shear strength).pdf
MCQ Soil mechanics questions (Soil shear strength).pdfMCQ Soil mechanics questions (Soil shear strength).pdf
MCQ Soil mechanics questions (Soil shear strength).pdf
Osamah Alsalih
 
ethical hacking-mobile hacking methods.ppt
ethical hacking-mobile hacking methods.pptethical hacking-mobile hacking methods.ppt
ethical hacking-mobile hacking methods.ppt
Jayaprasanna4
 
Democratizing Fuzzing at Scale by Abhishek Arya
Democratizing Fuzzing at Scale by Abhishek AryaDemocratizing Fuzzing at Scale by Abhishek Arya
Democratizing Fuzzing at Scale by Abhishek Arya
abh.arya
 
weather web application report.pdf
weather web application report.pdfweather web application report.pdf
weather web application report.pdf
Pratik Pawar
 
CME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional ElectiveCME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional Elective
karthi keyan
 
Automobile Management System Project Report.pdf
Automobile Management System Project Report.pdfAutomobile Management System Project Report.pdf
Automobile Management System Project Report.pdf
Kamal Acharya
 
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSE
TECHNICAL TRAINING MANUAL   GENERAL FAMILIARIZATION COURSETECHNICAL TRAINING MANUAL   GENERAL FAMILIARIZATION COURSE
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSE
DuvanRamosGarzon1
 
ethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.pptethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.ppt
Jayaprasanna4
 

Recently uploaded (20)

Railway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdfRailway Signalling Principles Edition 3.pdf
Railway Signalling Principles Edition 3.pdf
 
LIGA(E)11111111111111111111111111111111111111111.ppt
LIGA(E)11111111111111111111111111111111111111111.pptLIGA(E)11111111111111111111111111111111111111111.ppt
LIGA(E)11111111111111111111111111111111111111111.ppt
 
Forklift Classes Overview by Intella Parts
Forklift Classes Overview by Intella PartsForklift Classes Overview by Intella Parts
Forklift Classes Overview by Intella Parts
 
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
 
Halogenation process of chemical process industries
Halogenation process of chemical process industriesHalogenation process of chemical process industries
Halogenation process of chemical process industries
 
Immunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary AttacksImmunizing Image Classifiers Against Localized Adversary Attacks
Immunizing Image Classifiers Against Localized Adversary Attacks
 
DESIGN A COTTON SEED SEPARATION MACHINE.docx
DESIGN A COTTON SEED SEPARATION MACHINE.docxDESIGN A COTTON SEED SEPARATION MACHINE.docx
DESIGN A COTTON SEED SEPARATION MACHINE.docx
 
The Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdfThe Benefits and Techniques of Trenchless Pipe Repair.pdf
The Benefits and Techniques of Trenchless Pipe Repair.pdf
 
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
 
J.Yang, ICLR 2024, MLILAB, KAIST AI.pdf
J.Yang,  ICLR 2024, MLILAB, KAIST AI.pdfJ.Yang,  ICLR 2024, MLILAB, KAIST AI.pdf
J.Yang, ICLR 2024, MLILAB, KAIST AI.pdf
 
ASME IX(9) 2007 Full Version .pdf
ASME IX(9)  2007 Full Version       .pdfASME IX(9)  2007 Full Version       .pdf
ASME IX(9) 2007 Full Version .pdf
 
road safety engineering r s e unit 3.pdf
road safety engineering  r s e unit 3.pdfroad safety engineering  r s e unit 3.pdf
road safety engineering r s e unit 3.pdf
 
MCQ Soil mechanics questions (Soil shear strength).pdf
MCQ Soil mechanics questions (Soil shear strength).pdfMCQ Soil mechanics questions (Soil shear strength).pdf
MCQ Soil mechanics questions (Soil shear strength).pdf
 
ethical hacking-mobile hacking methods.ppt
ethical hacking-mobile hacking methods.pptethical hacking-mobile hacking methods.ppt
ethical hacking-mobile hacking methods.ppt
 
Democratizing Fuzzing at Scale by Abhishek Arya
Democratizing Fuzzing at Scale by Abhishek AryaDemocratizing Fuzzing at Scale by Abhishek Arya
Democratizing Fuzzing at Scale by Abhishek Arya
 
weather web application report.pdf
weather web application report.pdfweather web application report.pdf
weather web application report.pdf
 
CME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional ElectiveCME397 Surface Engineering- Professional Elective
CME397 Surface Engineering- Professional Elective
 
Automobile Management System Project Report.pdf
Automobile Management System Project Report.pdfAutomobile Management System Project Report.pdf
Automobile Management System Project Report.pdf
 
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSE
TECHNICAL TRAINING MANUAL   GENERAL FAMILIARIZATION COURSETECHNICAL TRAINING MANUAL   GENERAL FAMILIARIZATION COURSE
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSE
 
ethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.pptethical hacking in wireless-hacking1.ppt
ethical hacking in wireless-hacking1.ppt
 

Addressing modes of 8086

  • 1. ADDRESSING MODES OF 8086 1) Immediate addressing mode 2) Register addressing mode 3) Direct memory addressing mode 4) Register based indirect addressing mode 5) Register relative addressing mode 6) Base indexed addressing mode 7) Relative based indexed addressing mode 8) Implied addressing mode
  • 2. 1) Immediate addressing mode- • In this mode, the operand is specified in the instruction itself. Instructions are longer but the operands are easily identified. • Example: • MVI CL, 12H • This instruction moves 12 immediately into CL register. CL ← 12H
  • 3. 2) Register addressing mode- • In this mode, operands are specified using registers. This addressing mode is normally preferred because the instructions are compact and fastest executing of all instruction forms. • Registers may be used as source operands, destination operands or both. • Example: • MOV AX, BX • This instruction copies the contents of BX register into AX register. AX ← BX
  • 4. 3) Direct memory addressing mode • In this mode, address of the operand is directly specified in the instruction. Here only the offset address is specified, the segment being indicated by the instruction. • Example: • MOV CL, [4321H] • This instruction moves data from location 4321H in the data segment into CL. • The physical address is calculated as • DS * 10H + 4321 • Assume DS = 5000H • ∴PA = 50000 + 4321 = 54321H • ∴CL ← [54321H]
  • 5. 4) Register based indirect addressing mode • In this mode, the effective address of the memory may be taken directly from one of the base register or index register specified by instruction. If register is SI, DI and BX then DS is by default segment register. • If BP is used, then SS is by default segment register. • Example: • MOV CX, [BX] • This instruction moves a word from the address pointed by BX and BX + 1 in data segment into CL and CH respectively. • CL ← DS: [BX] and CH ← DS: [BX + 1] • Physical address can be calculated as DS * 10H + BX.
  • 6. 5) Register relative addressing mode- • In this mode, the operand address is calculated using one of the base registers and an 8 bit or a 16 bit displacement. • Example: • MOV CL, [BX + 04H] • This instruction moves a byte from the address pointed by BX + 4 in data segment to CL. • CL ← DS: [BX + 04H] • Physical address can be calculated as DS * 10H + BX + 4H.
  • 7. 6) Base indexed addressing mode- • Here, operand address is calculated as base register plus an index register. • Example: • MOV CL, [BX + SI] • This instruction moves a byte from the address pointed by BX + SI in data segment to CL. • CL ← DS: [BX + SI] • Physical address can be calculated as DS * 10H + BX + SI.
  • 8. 7) Relative based indexed addressing mode • In this mode, the address of the operand is calculated as the sum of base register, index register and 8 bit or 16 bit displacement. • Example: • MOV CL, [BX + DI + 20] • This instruction moves a byte from the address pointed by BX + DI + 20H in data segment to CL. • CL ← DS: [BX + DI + 20H] • Physical address can be calculated as DS * 10H + BX + DI + 20H.
  • 9. 8) Implied addressing mode • In this mode, the operands are implied and are hence not specified in the instruction. • Example: • STC • This sets the carry flag.