A Brief History of Microprocessors Lecture L11.0 Sections 1.1, 9.1

Some Microprocessors Intel 4004 Intel 8080 Motorola 6800 MOS Technology 6502 Intel 8088/8086 Motorola 6809 Motorola Intel Pentium

A Typical Computer System

The 8080 Microprocessor 40-pin chip Developed by Intel in Address Lines –Can address 2 16 = 64 Kbytes of memory 8 Data Lines Required +5V, +12V and -5V First microprocessor to become widely used

The 8080 Microprocessor PSW A C E L B D H SP PC Program Status Word Primary Accumulator Secondary Accumlators/ Data Counters Stack Pointer Program Counter

The 6800 Microprocessor 40-pin chip Developed by Motorola in address lines and 8 data lines Used only +5V

The 6800 Microprocessor Registers A B X PC SP CC Accumulator A Accumulator B Index register X Program counter Stack pointer Condition code register

The 6502 Microprocessor 40-pin chip Developed by MOS Technology, Inc. in address lines and 8 data lines Based on the Motorola 6800 Used in many home computers including the –Apple II –Commodore PET –Atari

The 6502 Microprocessor Registers A X Y PC SP Status Accumulator Index register X Index register Y Program counter Stack pointer Status register

The 8088/8086 Microprocessor 40-pin chip Developed by Intel in address lines –Can address 2 20 = 1 Mbyte of memory 8/16 multiplexed data lines in 8088/ used in the first IBM PC in 1981

8086 Registers

Computing 20-Bit Address bit segment address 16-bit offset address 20-bit actual or effective address + 4B D 4FDBD Segment address Offset address Actual address

8086 Segments Segment address Offset addresses within segment

The 6809 Microprocessor 40-pin chip Developed by Motorola in address lines and 8 data lines Used in the Radio Shack Color Computer Widely used in industrial controllers

The 6809 Microprocessor Registers AB Y S U DP Accumulator A:B = D Index register X Index register Y System stack pointer User stack pointer Program counter Direct page register Condition code register X CC PC

The Microprocessor 64-pin chip Developed by Motorola in address lines –Can address 2 24 = 16 Mbytes of memory 16 data lines Used in the original Macintosh Computer

The MicroprocessorRegisters D0 D1 D2 D3 D4 D5 D6 D7 Data Registers A0 A1 A2 A3 A4 A5 A6 A7 A7’ Address Registers Program Counter Status/CCR

1981IBM PC, uses Intel Motorola Motorola Intel MHz, 130,000 transistors 1984Motorola Bit address and data busses Integrated Microcontroller 1985Motorola 68HC Motorola MHz 1986Intel MHz, 275,000 transistors 1987Motorola Motorola MHz 1989Intel MHz, 1,000,000 transistors 1990Intel MHz 1992Intel Pentium4,000,000 Transistors 1997Motorola 68HC12Enhanced 68HC11

Intel Microprocessors pin DIP (dual in-line package) pin PGA (pin grid array) 80386DX pin PGA 80486DX pin PGA The Pentium pin PGA The Pentium Pro pin PGA

80486DX pin PGA

Some Intel Microprocessors

The Pentium Pro Registers

The Segment Register in the Protected Mode

The Descriptor Formats Base address = starting location of memory segment Limit = last offset address in segment G = granularity bit G = 0: Limit is length of 1 to 1M bytes G = 1: Limit is any multiple of 4K bytes Note: 2 20 x 4K = 2 20 x 2 12 = 2 32 = 4G bytes

DS register accesses memory locations H-1000FFH

1981IBM PC, uses Intel Motorola Motorola Intel MHz, 130,000 transistors 1984Motorola Bit address and data busses Integrated Microcontroller 1985Motorola 68HC Motorola MHz 1986Intel MHz, 275,000 transistors 1987Motorola Motorola MHz 1989Intel MHz, 1,000,000 transistors 1990Intel MHz 1992Intel Pentium4,000,000 Transistors 1997Motorola 68HC12Enhanced 68HC11

The 68HC11/12 RAMCPUEEPROM ROM/ EPROM TIMER PARALLEL I/O SPISCI A/D 68HC11/12

The 68HC12(11) Registers