A Brief History of Microprocessors Module M 13

A Brief History of Microprocessors Module M 13. 1 Sections 1. 1, 9. 1

Some Microprocessors • • Intel 4004 Intel 8080 Motorola 6800 MOS Technology 6502 Intel 8088/8086 Motorola 6809 Motorola 68000 Motorola 6811/12

A Typical Computer System

The 8080 Microprocessor • 40 -pin chip • Developed by Intel in 1974 • 16 Address Lines – Can address 216 = 64 Kbytes of memory • 8 Data Lines • Required +5 V, +12 V and -5 V • 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 1975 16 address lines and 8 data lines Used only +5 V

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 1976 16 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 1978 • 20 address lines – Can address 220 = 1 Mbyte of memory • 8/16 multiplexed data lines in 8088/8086 • 8088 used in the first IBM PC in 1981

8086 Registers

The 6809 Microprocessor • • • 40 -pin chip Developed by Motorola in 1979 16 address lines and 8 data lines Used in the Radio Shack Color Computer Widely used in industrial controllers

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

The 68000 Microprocessor • 64 -pin chip • Developed by Motorola in 1979 • 24 address lines – Can address 224 = 16 Mbytes of memory • 16 data lines • Used in the original Macintosh Computer

The 68000 Microprocessor. Registers 31 31 16 15 8 7 0 0 D 1 D 2 D 3 D 4 D 5 D 6 D 7 Data Registers A 0 A 1 Address A 2 A 3 Registers A 4 A 5 A 6 A 7’ Program Counter Status/CCR

1981 1982 1984 1985 1986 1987 1988 1989 1990 1992 1997 IBM PC, uses Intel 8088 Motorola 68010 Motorola 68008 Intel 80286 Motorola 68020 Motorola 68 HC 11 Motorola 68020 -- 25 MHz Intel 80386 Motorola 68030 -- 33 MHz Intel 80486 Intel Pentium Motorola 68 HC 12 10 MHz, 130, 000 transistors 32 -Bit address and data busses Integrated Microcontroller 16 MHz, 275, 000 transistors 25 MHz, 1, 000 transistors 50 MHz 4, 000 Transistors Enhanced 68 HC 11

The 68 HC 11/12 RAM CPU ROM/ EPROM EEPROM 68 HC 11/12 A/D TIMER PARALLEL I/O SPI SCI

The 68 HC 12(11) Registers