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19/1/2011 ES C263: MICROPROCESSOR PROGRAMMING AND INTERFACING

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ES C263: MICROPROCESSOR

PROGRAMMING AND INTERFACING

Lecture 5


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Last Lecture

Logical Partitions of MS-DOS Disk


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Today's Lecture

Introduction to Intel 8086 microprocessor Intel 8086 CPU Architecture


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Intel 8086 Microprocessor

Key Features: Released by Intel in 1978 Produced from 1978 to 1990s A 16-bit microprocessor chip. Max. CPU clock rate : 5 MHz to 10 MHz Instruction set: x86-16 Package: 40 pin DIP The 8086 gave rise to the x86 architecture of Intel's future processors. Common manufacturer(s): Intel, AMD, NEC, Fujitsu, Harris

(Intersil), OKI, Siemens AG, Texas Instruments, Mitsubishi. The Intel 8088, released in 1979, was a slightly modified chip

with an external 8-bit data bus and is notable as the processor used in the original IBM PC.

Fig1:Intel 8086 Microprocessor


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8086 CPU Chip

Fig1: 8086 CPU Chip in DIP Package Fig2: CPU Chip


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Intel 8086 architecture

The architecture was defined by Stephen P. Morse with some help and assistance by Bruce Ravenel (the architect of the 8087) in refining the final revisions. Logic designer Jim McKevitt and John Bayliss were the lead engineers of the hardware-level development team and William Pohlman the manager for the project.

The legacy of the 8086 is enduring in the basic instruction set of today's personal computers and servers; the 8086 also lent its last two digits to later extended versions of the design, such as the Intel 286 and the Intel 386, all of which eventually became known as the x86 family.


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Intel 8086 Process Technology

It was implemented using depletion-load nMOS circuitry with approximately 20,000 active transistors (29,000 counting all ROM and PLA sites).

It was soon moved to a new refined nMOS manufacturing process called HMOS (for High performance MOS) that Intel originally developed for manufacturing of fast static RAM products.

This was followed by HMOS-II, HMOS-III versions, and, eventually, a fully static CMOS version for battery-powered devices, manufactured using Intel's CHMOS processes.

The original chip measured 33 mm² (assume a square of side length=0.57cm) and minimum feature size was 3.2 μm.


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Why Choose the Intel 8086? There is need to study a microprocessor. How it works, what is its

architecture, what is its instruction set architecture, how it is programmed, how it is interfaced with other devices etc. etc.

8086 is first x86 microprocessor. The term x86 refers to a family of instruction set architectures based

on the Intel 8086 CPU. The 8086 was launched in 1978 as a fully 16-bit extension of Intel's early 8-bit based microprocessors and also introduced segmentation to overcome the 16-bit addressing barrier of earlier chips. The term x86 derived from the fact that early successors to the 8086 also had names ending in "86". Many additions and extensions have been added to the x86 instruction set over the years, almost consistently with full backward compatibility.The architecture has been implemented in processors from Intel, Cyrix, AMD, VIA, and many others.

The PC market which uses Intel based devices takes up some 60% of the total microprocessor market! The other main processor used by industry is the Motorola 68000 family of microprocessors.


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Current x86 processorshttp://en.wikipedia.org/wiki/8086

x86-32: EP80579 · Intel CE · Atom x86-64: Atom (some) · Celeron · Pentium (

Dual-Core) · Core (i3 · i5 · i7) · Xeon Other: IOP · Itanium x86 Assemblers: A86/A386 · FASM · GAS ·

HLA · MASM · NASM · TASM · WASM · YASM

http://en.wikipedia.org/wiki/X86_architecture


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8086 kit

Key features of this trainer kit are such as: 8086/8088 CPU operating at 2.5/5 MHz. 16 KB RAM with Battery backup expandable upto 256

KB. 16 KB powerful monitor EPROM. 24 I/O lines using 8255. 16 bit Timer/Counter using 8253. RS-232C Interface using 8251. 8259 Interrupt Controller. 27 Series EPROM Programmer. Printer Interface [Optional].

These kits are prepared and supplied bymany suppliers in India also for training and education purpose.

Fig: 8086 kit


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http://www.flite.co.uk/the-flite-8086-an-introduction.htm http://www.flite.co.uk/flite-flt-86-8086-training-system.htm

System Overview The 8086 is probably the most commonly used 16-bit

microprocessor of all time, with the upwardly compatible families of microprocessors developed from it now at the heart of the virtually all personal computers. This makes the 8086 the number one choice as a platform for teaching microprocessor principles on many computer science courses.

Fig1: 8086 kit

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The FLT86 is a well established training system for the 8086 CPU still being manufactured by Flite Electronics International Limited in Southampton, England.


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8086 microprocessor

16 bit- microprocessor ? 16-bits data bus?

Microprocessor 8086

DataBus

Control signals

AddBus

Address Bus – 20 lines – A19 – A0

Data Bus – 16 lines – D15 – D0


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20 bits address bus? It can address any one of

1,048,576 (=220 ) memory locations/addresses.

Each memory location is one byte wide.

To store a word of 16 bit 2 memory locations are required.

If the first byte of the word is at even address 8086 can read the entire word in one operation.

If the first byte of the word is at an odd address, the 8086 will read the first byte with one bus operation and the second byte with another bus operation.

1,048,576 memory locations=1MBytes

A19……………A0

0……………….0 00000H

1……………….1 FFFFFH

MemoryAddressSpace

00000H

FFFFFH


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8086 INTERNAL ARCHITECTURE

Fig: 8086 Internal block diagram .

2 units are: 1. BIU 2. EU


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BIU and EU

BIU (bus interface unit) sends out addresses, fetches instructions from memory, reads data from ports and memory, and writes data to ports and memory. In other words, the BIU handles all transfers of data and addresses on the buses for the execution unit.

EU (execution unit) of the 8086 tells the BIU where to fetch instructions or data from, decodes instructions, and executes instructions.

L5

Documents

8086 cpu chip

execution unit

es c263

bus operation

microprocessor programming

personal computers

intel 8086 microprocessor

microprocessor