Intel 8086 Hardware Architecture Pdf Download: The Ultimate Resource for Microprocessor Enthusiasts
Intel 8086 Hardware Architecture Pdf Download
Are you interested in learning about one of the most influential microprocessors in history? Do you want to understand how the Intel 8086 works and what makes it so powerful? Do you wish to download a pdf file that explains the hardware architecture of Intel 8086 in detail? If you answered yes to any of these questions, then this article is for you!
Intel 8086 Hardware Architecture Pdf Download
In this article, we will cover the following topics:
What is Intel 8086?
Why is Intel 8086 important?
How does Intel 8086 work?
How to learn more about Intel 8086?
By the end of this article, you will have a clear understanding of the hardware architecture of Intel 8086 and how to access more resources on this topic. So, let's get started!
What is Intel 8086?
Intel 8086 is a microprocessor that was introduced by Intel Corporation in 1978. It was the first member of the x86 family of processors, which are still widely used today. It was also the first microprocessor to use a 16-bit data bus and a 20-bit address bus, allowing it to access up to 1 MB of memory.
The Intel 8086 was designed as an enhanced version of the previous Intel 8080 microprocessor, which was an 8-bit processor with a limited memory capacity. The Intel 8086 was compatible with most of the software written for the Intel 8080, but also offered new features and capabilities that made it more suitable for complex applications.
The main features of Intel 8086 are:
A clock speed of up to 10 MHz
A data bus width of 16 bits
An address bus width of 20 bits
A register set consisting of four segment registers, four general purpose registers, an instruction pointer, a flag register, and an arithmetic logic unit
A pipelined architecture consisting of two units: the bus interface unit (BIU) and the execution unit (EU)
A set of 246 instructions, including arithmetic, logical, data transfer, control transfer, string manipulation, and interrupt handling instructions
A support for external coprocessors, such as the Intel 8087 floating-point unit and the Intel 8089 input/output processor
Why is Intel 8086 important?
The Intel 8086 is considered to be one of the most important microprocessors in history because of its impact on the development of personal computers and software. The Intel 8086 was the basis for the IBM PC, which was the first widely successful personal computer that standardized the hardware and software platforms for the industry. The IBM PC used the Intel 8086 as its central processing unit (CPU) and ran the MS-DOS operating system, which was based on the CP/M operating system that was originally designed for the Intel 8080.
The popularity of the IBM PC and its clones led to the creation of a large market for software and hardware compatible with the Intel 8086 and its successors. Many software developers wrote programs for the Intel 8086 using assembly language or high-level languages such as C, Pascal, BASIC, and FORTRAN. Some of the most famous software products that were developed for the Intel 8086 include Microsoft Word, Lotus 1-2-3, VisiCalc, AutoCAD, Turbo Pascal, and Borland C++.
The legacy of the Intel 8086 is still evident today, as most of the modern processors are based on the x86 architecture that originated from the Intel 8086. The x86 architecture has evolved over time to include new features and extensions, such as 32-bit and 64-bit modes, protected mode, real mode, virtual mode, paging, segmentation, multitasking, multiprocessing, floating-point operations, multimedia operations, and encryption operations. However, the core instruction set and register set of the x86 architecture are still compatible with those of the Intel 8086.
How does Intel 8086 work?
The Intel 8086 works by executing a sequence of instructions that are stored in memory. Each instruction consists of one or more bytes that specify the operation to be performed and the operands to be used. The operands can be constants, registers, memory locations, or ports. The instructions can be classified into six groups: data transfer instructions, arithmetic instructions, logical instructions, control transfer instructions, string manipulation instructions, and interrupt handling instructions.
To execute an instruction, the Intel 8086 uses two internal units: the bus interface unit (BIU) and the execution unit (EU). The BIU is responsible for fetching instructions from memory and transferring data between memory and registers. The EU is responsible for decoding and executing instructions and performing arithmetic and logical operations. The BIU and the EU operate in parallel using a pipelined architecture that increases the performance of the processor.
The Bus Interface Unit (BIU)
The BIU consists of four segment registers, an instruction pointer, an instruction queue, and a bus controller. The segment registers are used to divide the memory into four segments: code segment (CS), data segment (DS), stack segment (SS), and extra segment (ES). Each segment register holds a 16-bit value that represents the base address of a segment. The instruction pointer (IP) holds a 16-bit value that represents the offset address of the next instruction to be executed within the code segment. The instruction queue is a six-byte buffer that stores the prefetched instructions from memory. The bus controller is a circuit that controls the communication between the processor and external devices via the data bus and address bus.
The Segment Registers
The segment registers are used to access memory in a segmented manner. Each segment register defines a 64 KB segment of memory that can be accessed by adding a 16-bit offset value to it. For example, if CS = F000h and IP = 0100h, then the next instruction to be executed is located at F000h + 0100h = F100h in memory. Similarly, if DS = A000h and BX = 0200h, then a data value can be accessed at A000h + 0200h = A200h in memory.
The segment registers can be loaded with any value by using special instructions such as LDS (load DS with pointer), LES (load ES with pointer), PUSH (push register onto stack), POP (pop register from stack), MOV (move data between registers or memory), etc. However, some segment registers are automatically updated by certain instructions or events. For example:
The Instruction Pointer
The instruction pointer (IP) is a 16-bit register that holds the offset address of the next instruction to be executed within the code segment. The IP is automatically incremented by the length of the current instruction after it is fetched from memory. The IP can also be modified by control transfer instructions such as JMP (jump), CALL (call subroutine), RET (return from subroutine), INT (interrupt), etc. For example, if CS = F000h and IP = 0100h, then the next instruction to be executed is located at F000h + 0100h = F100h in memory. If the instruction at F100h is JMP 0200h, then the IP is updated to 0200h and the next instruction to be executed is located at F000h + 0200h = F200h in memory.
The Instruction Queue
The instruction queue is a six-byte buffer that stores the prefetched instructions from memory. The BIU fetches instructions from memory and places them in the instruction queue while the EU is executing the previous instructions. This way, the EU does not have to wait for the BIU to fetch the next instruction and can execute them faster. The instruction queue can hold up to six bytes of instructions, which means that it can store one to six instructions depending on their length. The instruction queue is emptied when a control transfer instruction or an interrupt occurs.
The Execution Unit (EU)
The EU consists of four general purpose registers, a flag register, and an arithmetic logic unit (ALU). The general purpose registers are used to store data values and operands for arithmetic and logical operations. The flag register is used to store the status of the previous operation and to control conditional branching. The ALU is used to perform arithmetic and logical operations on data values and operands.
The General Purpose Registers
The general purpose registers are AX, BX, CX, and DX. Each register is 16 bits wide and can store a 16-bit data value or operand. Each register can also be divided into two 8-bit registers: AH and AL for AX, BH and BL for BX, CH and CL for CX, and DH and DL for DX. The 8-bit registers can be used to store 8-bit data values or operands or to access individual bytes of memory.
The general purpose registers can be used for various purposes depending on the instruction. For example:
The AX register is used as an accumulator for arithmetic and logical operations, such as ADD (add), SUB (subtract), MUL (multiply), DIV (divide), AND (logical AND), OR (logical OR), etc.
The BX register is used as a base register for addressing memory locations, such as MOV [BX], AL (move AL to memory location pointed by BX).
The CX register is used as a counter for loop and string operations, such as LOOP (loop until CX becomes zero), REP (repeat string operation until CX becomes zero), etc.
The DX register is used as a data register for input/output operations, such as IN (input from port), OUT (output to port), etc.
The Flag Register
The flag register is a 16-bit register that holds nine flags that indicate the status of the previous operation and control conditional branching. The flags are:
Carry flag (CF): Set if there is a carry or borrow out of the most significant bit of the result.
Parity flag (PF): Set if there is an even number of 1 bits in the least significant byte of the result.
Auxiliary carry flag (AF): Set if there is a carry or borrow out of bit 3 of the result.
Zero flag (ZF): Set if the result is zero.
Sign flag (SF): Set if the most significant bit of the result is 1.
Trap flag (TF): Set if single-step mode is enabled for debugging purposes.
Interrupt enable flag (IF): Set if external interrupts are enabled.
Direction flag (DF): Set if string operations are performed from high address to low address.
Overflow flag (OF): Set if there is a signed overflow in the result.
The flag register can be manipulated by using special instructions such as CLC (clear carry flag), STC (set carry flag), CLI (clear interrupt enable flag), STI (set interrupt enable flag), CLD (clear direction flag), STD (set direction flag), etc. The flag register can also be tested by using conditional jump instructions such as JC (jump if carry), JZ (jump if zero), JS (jump if sign), JO (jump if overflow), etc.
The Arithmetic Logic Unit (ALU)
The ALU is a circuit that performs arithmetic and logical operations on data values and operands. The ALU can perform the following operations:
Addition and subtraction, with or without carry or borrow
Multiplication and division, with or without sign extension
Logical AND, OR, XOR, and NOT
Shift and rotate, with or without carry
Increment and decrement
Compare and test
The ALU operates on data values and operands that are stored in the general purpose registers or memory locations. The ALU also updates the flag register according to the result of the operation.
How to learn more about Intel 8086?
If you want to learn more about Intel 8086 hardware architecture, there are many resources and tips that you can use. Here are some of them:
Books and manuals
One of the best ways to learn about Intel 8086 hardware architecture is to read books and manuals that explain it in detail. Some of the books and manuals that you can read are:
TitleAuthorDescription
The 8086/8088 Primer: An Introduction to Their Architecture, System Design, and ProgrammingStephen P. MorseA comprehensive introduction to the Intel 8086/8088 microprocessors, covering their history, features, architecture, instruction set, programming, interfacing, and applications.
The 8086 Book: Hardware, Software, Programming, and InterfacingLance A. LeventhalA complete guide to the Intel 8086 microprocessor, covering its hardware design, software development, programming techniques, and interfacing methods.
The Intel Microprocessors: 8086/8088, 80186/80188, 80286, 80386, 80486 Pentium, Pentium Pro Processor, Pentium II, Pentium III, Pentium 4, and Core2 with 64-bit ExtensionsBarry B. BreyA comprehensive textbook on the Intel microprocessors from the Intel 8086 to the Core2 with 64-bit extensions, covering their architecture, programming, interfacing, and applications.
Intel Microprocessors: Hardware Interfacing And Applications With The 8086 Family Of MicroprocessorsMuhammad Ali Mazidi and Janice Gillispie MazidiA practical book on the Intel microprocessors from the Intel 8086 to the Pentium II, covering their hardware interfacing and applications with various devices and systems.
Intel 8086/8088 User's Manual: Programmer's And Hardware ReferenceIntel CorporationThe official user's manual for the Intel 8086/8088 microprocessors from Intel Corporation, covering their specifications, architecture, instruction set, programming model, system design guidelines, and application examples.
Online courses and tutorials
Another way to learn about Intel 8086 hardware architecture is to take online courses and tutorials that teach it in an interactive and engaging way. Some of the online courses and tutorials that you can take are:
TitleProviderDescription
Introduction to Microprocessors: The Intel 8086 Architecture And Assembly Language ProgrammingCourseraA beginner-level course that introduces the basics of microprocessors and teaches the Intel 8086 architecture and assembly language programming.
Microprocessor Architecture And Interfacing: The Intel 8086 And Its PeripheralsNPTELAn intermediate-level course that covers the microprocessor architecture and interfacing of the Intel 8086 and its peripherals such as memory, input/output devices, timers, interrupts, etc.
UdemyAn advanced-level course that covers the microprocessor design and applications of the Intel 8086 and its applications in embedded systems and robotics.
Intel 8086 Assembly Language ProgrammingTutorialsPointA free online tutorial that teaches the Intel 8086 assembly language programming with examples and exercises.
Intel 8086 Hardware ArchitectureGeeksforGeeksA free online tutorial that explains the Intel 8086 hardware architecture with diagrams and illustrations.
Simulators and emulators
A third way to learn about Intel 8086 hardware architecture is to use simulators and emulators that allow you to practice Intel 8086 programming and debugging in a virtual environment. Some of the simulators and emulators that you can use are:
TitleDescription
emu8086A microprocessor emulator that simulates the Intel 8086 microprocessor and its peripherals. It also provides an integrated development environment (IDE) that supports assembly language programming, debugging, and testing.
Easy Code for MASMA visual assembly IDE that supports the Microsoft Macro Assembler (MASM) for the Intel 8086 microprocessor. It also provides a graphical user interface (GUI) designer, a code editor, a debugger, and a simulator.
PCjs MachinesA collection of online emulators that emulate various machines based on the Intel 8086 microprocessor, such as the IBM PC, the IBM PC XT, the IBM PC AT, etc. It also provides access to various software programs and games that run on these machines.
Sim8086A web-based simulator that simulates the Intel 8086 microprocessor and its instruction set. It also provides a code editor, a debugger, and a memory viewer.
emuStudioA modular emulator platform that supports various emulators for different microprocessors, including the Intel 8086. It also provides a graphical user interface (GUI) that allows users to configure and run the emulators.
Conclusion
In this article, we have learned about the Intel 8086 hardware architecture pdf download. We have covered the following topics:
What is Intel 8086?
Why is Intel 8086 important?
How does Intel 8086 work?
How to learn more about Intel 8086?
We hope that this article has given you a clear understanding of the hardware architecture of Intel 8086 and how to access more resources on this topic. If you are interested in learning more about Intel 8086 hardware architecture pdf download, you can use the links provided in this article or search for more online.
Thank you for reading this article and happy learning!
Frequently Asked Questions (FAQs)
Here are some of the most frequently asked questions about Intel 8086 hardware architecture pdf download:
Q: Where can I download a pdf file that explains the hardware architecture of Intel 8086 in detail?
A: There are many sources where you can download a pdf file that explains the hardware architecture of Intel 8086 in detail. Some of them are:
The official user's manual for the Intel 8086/8088 microprocessors from Intel Corporation: https://archive.org/details/bitsavers_inteldataSManual_5953774
The book "The 8086/8088 Primer: An Introduction to Their Architecture, System Design, and Programming" by Stephen P. Morse: https://archive.org/details/The_80868088_Primer_An_Introduction_to_Their_Architecture_System_Design_and_Programming
The book "The 8086 Book: Hardware, Software, Programming, and Interfacing" by Lance A. Leventhal: https://archive.org/details/The_8086_Book_Hardware_Software_Programming_and_Interfacing
The book "The Intel Microprocessors: 8086/8088, 80186/80188, 80286, 80386, 80486 Pentium, Pentium Pro Processor, Pentium II, Pentium III, Pentium 4, and Core2 with 64-bit Extensions" by Barry B. Brey: https://archive.org/details/The_Intel_Microprocessors_8th_Edition
The book "Intel Microprocessors: Hardware Interfacing And Applications With The 8086 Family Of Microprocessors" by Muhammad Ali Mazidi and Janice Gillispie Mazidi: https://archive.org/details/IntelMicroprocessorsHardwareInterfacingAndApplicationsWithThe8086FamilyOfMicroprocessors
Q: How can I practice Intel 8086 programming and debugging?
A: You can practice Intel 8086 programming and debugging by using simulators and emulators that allow you to write and run assembly co