1. Computer Organization and Assembly language
Lecture 3
Evolution of Computers
Intel Family Architecture
Course Instructor: Aisha Danish

2. What are microprocessors?
A microprocessor is a processor (or Central Processing Unit, CPU) fabricated on a single integrated circuit. X Y
Control
unit IR PC
ALU
ACC
MAR
Data bus
Control bus
Address bus
A simple microprocessor architecture

3. Evolution of Computers
First generation ( ) - vacuum tube
Second generation ( ) - transistor
Third generation ( ) - IC
Fourth generation (1971-present) - microprocessor

4. Evolution of Computers
First generation ( ) - vacuum tube
IBM 650, 1954

5. Evolution of Computers
Second generation ( ) - transistor
Manchester University Experimental Transistor Computer

6. Evolution of Computers
Third generation ( ) - IC
PDP-8, Digital Equipment Corporation
Thanks to the use of ICs, the DEC PDP is the least expensive general purpose small computer in 1960s

7. Evolution of Computers
Fourth generation (1971-present) - microprocessor
In 1971, Intel developed 4-bit chip for calculator applications.
ALU
Instruction
decoder
Reg.
Program
counter
I/O
Refresh
logic
System bus
Control logic
ROM/RAM buffer
Timing
Reset
Block diagram of Intel 4004
4004 chip layout
A good review article: The History of The Microprocessor, Bell Labs Technical Journal,
Autumn, 1997

8. Evolution of Intel Microprocessors
Number of transistors
Minimum transistor sizes (µm)
8080
8088
80286
80386
80486
Pentium
P II
P III
P 4
8080
8088
80286
80386
80486
Pentium
P II
P III
P 4
Clock frequencies (MHz)
MIPS
8080
8088
80286
80386
80486
Pentium
P II
P III
P 4
8080
8088
80286
80386
80486
Pentium
P II
P III
P 4

9. 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)
     

10. Applications of Microprocessors
Computers
System performance is normally the most important design concern
Memory
Timing &
control
Keyboard
Interrupt
...
Monitor
Micro-
processor
Disk
Other
peripherals
Bus
Block diagram of a computer

11. Applications of Microprocessors
Microcontrollers
A microcontroller is a simple computer implemented in a single VLSI chip.
CPU
RAM
ROM
Timer
Interrupt
I/O port
USART
A/D, D/A
OSC.
In general, microcontrollers are cheap and have low performance
Microcontrollers are widely used in industrial control, automobile and home applications
Block diagram of a microcontroller

12. 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

13. 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.

14. 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.

15. The 8086 Family
The & 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 & microprocessors. −The 80186/80188 integrates on a single chip an 8086/8088 microprocessor and all the chips mentioned above. −The & are often referred to as highintegration processors

16. The 8086 Family
The Microprocessor (1982): −24-bit address bus. −16-bit internal data bus. −16-bit external data bus. −Designed to be software compatible with 8086 & microprocessors. −Provides two programming modes: Real Mode Protected Mode

17. The 8086 Family
The Microprocessor (Real Mode): −The processor function exactly like the 8086 processor. −That is, any 8086 program can be run on a Real Mode processor without any change. −The processor uses only its 20 least significant address lines. −So, the memory space is limited to 1 MB

18. The 8086 Family
The 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

19. 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

20. The 8086 Family
The 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 −Pipelined design

21. 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