COMPUTER ORGANIZATION
AND ASSEMBLY LANGUAGE
Lecture 3
Evolution of Computers
Intel Family Architecture
Course Instructor: Aisha Danish
What are microprocessors?
 A microprocessor is a processor (or Central Processing Unit, CPU)
fabricated on a single integrated circuit.
Address bus
MAR
PC
IR
Control
unit
Control bus
X
Data bus
Y
ALU
ACC
A simple microprocessor architecture
1-2
Evolution of Computers
 First generation (1939-1954) - vacuum tube
 Second generation (1954-1959) - transistor
 Third generation (1959-1971) - IC
 Fourth generation (1971-present) - microprocessor
Http://history.acusd.edu/gen/recording/computer1.html
1-3
Evolution of Computers
 First generation (1939-1954) - vacuum tube
IBM 650, 1954
Http://history.acusd.edu/gen/recording/computer1.html
http://www.cs.virginia.edu/brochure/museum.html
http://www.columbia.edu/acis/history/650.html
1-4
Evolution of Computers
 Second generation (1954-1959) - transistor
Manchester University Experimental Transistor Computer
Http://history.acusd.edu/gen/recording/computer1.html
http://www.computer50.org/kgill/transistor/trans.html
1-5
Evolution of Computers
 Third generation (1959-1971) - IC
PDP-8, Digital Equipment Corporation
 Thanks to the use of ICs, the DEC PDP-8
is the least expensive general purpose small
computer in 1960s
Http://history.acusd.edu/gen/recording/computer1.html
http://www.piercefuller.com/collect/pdp8.html
1-6
Evolution of Computers
 Fourth generation (1971-present) - microprocessor
 In 1971, Intel developed 4-bit 4004 chip for calculator
applications.
ROM/RAM buffer
Timing
Reset
Control logic
Program
counter
Instruction
decoder
ALU
Reg.
I/O
Refresh
logic
http://www.intel.com
System bus
Block diagram of Intel 4004
1-7
4004 chip layout
A good review article: The History of The Microprocessor, Bell Labs Technical Journal,
Autumn, 1997
Evolution of Intel Microprocessors
Minimum transistor sizes (µm)
Number of transistors
100,000,000
80386
1,000,000
8088
100,000
10,000
1,000
P III
Pentium
10,000,000
80486
7
P4
P II
8080
6
5
4
80286
8088
3
8080
80386
2
100
80286
1
10
80486
0
1
1974 1979
1982 1985
1989
1993 1997
1974
1999 2000
1979
1982
1985
Clock frequencies (MHz)
P4
P II
Pentium
10
8088
Pentium
1997
1999
2000
80486
1 8080 8088
80286
P4
P II
80386 80486
10
1
80286
0.1
1974
1-8
P4
P III
100
P III
80386
8080
1993
P III
10000
1000
100
1989
P II
MIPS
10000
1000
Pentium
1979
1982
1985
1989
1993
1997
1999
2000
1974 1979 1982 1985 1989 1993 1997 1999 2000
Other Commercial Microprocessors
 PowerPC (IBM, Motorola)
 Athlon, Dulon, Hammer (AMD)
 Crusoe (Transmeta)
 SPARC, UltraSPARC (Sun Microsystems)
 TI’s TMS DSP chips (Texas Instruments)
 StarCore (Motorola, Agere)
 ARM cores (Advanced RISC Machines)
 MIPS cores (MIPS Technologies)
 
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Applications of Microprocessors
 Computers
 System performance is normally the most important design concern
...
Keyboard
Monitor
Disk
Other
peripherals
Bus
Microprocessor
Memory
Timing &
control
Block diagram of a computer
1-10
...
Interrupt
control
Applications of Microprocessors
 Microcontrollers
 A microcontroller is a simple
computer implemented in a
single VLSI chip.
 In general, microcontrollers
are cheap and have low
performance
 Microcontrollers are widely
used in industrial control,
automobile and home
applications
OSC.
RAM
ROM
CPU
I/O port
Timer
USART
Interrupt
A/D, D/A
Block diagram of a microcontroller
1-11
What is a microprocessor?

Criteria






number of chips
data path
address space
CPU performance
Price
Types of micrprocessor

Application



Reprogrammable microprocessors
embedded microprocessors and microcontrollers
Instruction complexity


CISC
RISC
The 8086 Family
The 8086 Microprocessor (1978):
−20-bit address bus.
−16-bit internal data bus.
−16-bit external data bus.
−Separate bus interface unit (BIU) and execution unit
(EU).
−16-bit registers (with the ability to access the high or
low 8 bits separately).
−Built in hardware multiply and divide instructions.
−Support for an external floating-point math
coprocessor.
The 8086 Family
The 8088 Microprocessor (1979):
−20-bit address bus.
−16-bit internal data bus.
−8-bit external data bus.
−Separate bus interface unit (BIU) and execution unit
(EU).
−16-bit registers (with the ability to access the high or
low 8 bits separately).
−Built in hardware multiply and divide instructions.
−Support for an external floating-point math
coprocessor.
The 8086 Family
The 80186 & 80188 Microprocessors (1982):
−A personal computer (PC) based on the 8086/8088
microprocessors requires several additional chips such
as: a clock generator, a programmable timer, a programmable
interrupt controller, a direct memory access controller and a
circuitry to select the I/O devices.
−To simplify the design, Intel introduced the 80186 &
80188 microprocessors.
−The 80186/80188 integrates on a single chip an
8086/8088 microprocessor and all the chips mentioned
above.
−The 80186 & 80188 are often referred to as highintegration
processors
The 8086 Family
The 80286 Microprocessor (1982):
−24-bit address bus.
−16-bit internal data bus.
−16-bit external data bus.
−Designed to be software compatible with 8086 &
80186 microprocessors.
−Provides two programming modes:
Real Mode
Protected Mode
The 8086 Family
The 80286 Microprocessor (Real Mode):
−The processor function exactly like the 8086
processor.
−That is, any 8086 program can be run on a Real
Mode 80286 processor without any change.
−The 80286 processor uses only its 20 least significant
address lines.
−So, the memory space is limited to 1 MB
The 8086 Family
The 80286 Microprocessor (Protected Mode):
−In this mode, the processor supports a multiprogram
environment.
−It gives each program a predetermined amount of
memory.
−This uses the full memory space which is 16MB.
−This mode is called Protected Mode because several
programs can be loaded into memory at once (each in its
own segment), but are protected from each other
The 8086 Family
The 80386 Microprocessor (1984):
−32-bit address bus.
−32-bit internal data bus.
−32-bit external data bus.
−32-bit registers.
−Provides three modes:
 Real Mode (identical to that of 80286)
 Protected Mode (manages 4 GB of memory in a way
similar to that of the 80286).
 Virtual Mode (similar to Real Mode, except that
multiple 8086 processors can run simultaneously
The 8086 Family
The 80486 Microprocessor (1989):
−32-bit address bus.
−32-bit internal and external data bus.
−32-bit registers.
−On-chip cache (stores the most recently used
instructions and data )
−Integrated Floating-Point Unit (FPU)
−Real & Protected Modes as in 80386
−Pipelined design
The 8086 Family
The Pentium Microprocessor (1993):
−32-bit address bus.
−32-bit internal
−64-bit external data bus.
−32-bit registers.
−Two instructions pipelines
−On-chip cache
−Integrated FPU