"1100000001 ORG ; ONE The x86 MicroprocessorOBJECTIVES this chapter enables the student to: • Describe the Intel family of microprocessors from ® 8085 to Pentium . – In terms of bus size, physical memory & special features. • Explain the function of the EU (execution unit) andBIU (bus interface unit). • Describe pipelining and how it enables the CPU to work faster. • List the registers of the 8086. • Code simple MOV and ADD instructions. – Describe the effect of these instructions on their operands.OBJECTIVES (cont) this chapter enables the student to: • State the purpose of the code segment,datasegment,stack segment, and extra segment. • Explain the difference between a logical addressand a physical address. • Describe the "little endian" storage convention of x86 microprocessors. • State the purpose of the stack. • Explain the function of PUSH and POP instructions. • List the bits of the flag register and briefly state thepurpose of each bit.OBJECTIVES (cont) this chapter enables the student to: • Demonstrate the effect of ADD instructions on the flag register. • List the addressing modes of the 8086 andrecognize examples of each mode. • Know how to use flowcharts and pseudocode inprogram development.1.1 BRIEF HISTORY OF THE x86 FAMILYevolution from 8080/8085 to 8086 • In 1978, Intel Corporation introduced the 16-bit8086 microprocessor, a major improvement overthe previous generation 8080/8085 series. – The 8086 capacity of 1 megabyte of memory exceededthe 8080/8085 maximum of 64K bytes of memory. – 8080/8085 was an 8-bit system, which could work on only 8 bits of data at a time. • Data larger than 8 bits had to be broken into 8-bit pieces to be processed by the CPU. – 8086 was a pipelined processor, as opposed to thenonpipelined 8080/8085.1.1 BRIEF HISTORY OF THE x86 FAMILYevolution from 8080/8085 to 80861.1 BRIEF HISTORY OF THE x86 FAMILYevolution from 8086 to 8088 • The 8086 microprocessor has a 16-bit data bus,internally and externally. – All registers are 16 bits wide, and there is a 16-bit data bus to transfer data in and out of the CPU • There was resistance to a 16-bit external bus as peripherals were designed around 8-bit processors. • A printed circuit board with a 16-bit data also bus cost more. • As a result, Intel came out with the 8088 version. – Identical to the 8086, but with an 8-bit data bus. • Picked up by IBM as the microprocessor in designing the PC.1.1 BRIEF HISTORY OF THE x86 FAMILYsuccess of the 8088 • The 8088-based IBM PC was an great success, because IBM & Microsoft made it an open system. – Documentation and specifications of the hardware and software of the PC were made public • Making it possible for many vendors to clone the hardwaresuccessfully & spawn a major growth in both hardware andsoftware designs based on the IBM PC.1.1 BRIEF HISTORY OF THE x86 FAMILY80286, 80386, and 80486 • Intel introduced the 80286 in 1982, which IBMpicked up for the design of the PC AT. – 16-bit internal & external data buses. 24 – 24 address lines, for 16mb memory. (2 = 16mb) – Virtual memory. • 80286 can operate in one of two modes: – Real mode - a faster 8088/8086 with the same maximumof 1 megabyte of memory. – Protected mode - which allows for 16M of memory. • Also capable of protecting the operating system & programsfrom accidental or deliberate destruction by a user.1.1 BRIEF HISTORY OF THE x86 FAMILY80286, 80386, and 80486 • Virtual memory is a way of fooling the processorinto thinking it has access to an almost unlimitedamount of memory. – By swapping data between disk storage and RAM.1.1 BRIEF HISTORY OF THE x86 FAMILY80286, 80386, and 80486 • In 1985 Intel introduced 80386 (or 80386DX). – 32-bit internally/externally, with a 32-bit address bus. 32 – Capable of handling memory of up to 4 gigabytes. (2 ) 46 – Virtual memory increased to 64 terabytes. (2 ) • Later Intel introduced 386SX, internally identical, butwith a 16-bit external data bus & 24-bit address bus. – This makes the 386SX system much cheaper. • Since general-purpose processors could not handlemathematical calculations rapidly, Intel introducednumeric data processing chips. – Math coprocessors, such as 8087, 80287, 80387.1.1 BRIEF HISTORY OF THE x86 FAMILY80286, 80386, and 80486 • On the 80486, in 1989, Intel put a greatly enhanced80386 & math coprocessor on a single chip. – Plus additional features such as cache memory. • Cache memory is static RAM with a very fast access time. • All programs written for the 8088/86 will run on 286, 386, and 486 computers.1.1 BRIEF HISTORY OF THE x86 FAMILY80286, 80386, and 804861.1 BRIEF HISTORY OF THE x86 FAMILY® ® Pentium & Pentium Pro ® • In 1992, Intel released the Pentium . (not 80586) – A name can be copyrighted, but numbers cannot. ® • On release, Pentium had speeds of 60 & 66 MHz. – Designers utilized over 3 million transistors on the® Pentium chip using submicron fabrication technology. – New design features made speed twice that of 80486/66. • Over 300 times faster than that of the original 8088. ® • Pentium is fully compatible with previous x86processors but includes several new features. – Separate 8K cache memory for code and data. – 64-bit bus, and a vastly improved floating-point processor.1.1 BRIEF HISTORY OF THE x86 FAMILY® ® Pentium & Pentium Pro ® • The Pentium is packaged in a 273-pin PGA chip – BICMOS technology, combines the speed of bipolartransistors with power efficiency of CMOS technology – 64-bit data bus, 32-bit registers & 32-bit address bus. • Capable of addressing 4gb of memory. ® • In 1995 Intel Pentium Pro was released—the sixthgeneration x86. – 5.5 million transistors. – Designed primarily for 32-bit servers & workstations."