Computer Organization and
Architecture
Instructor: Dr. Raqibul Hasan
Computer Architecture
■ It is the science and art of designing
computing platforms (hardware, interface,
system SW, and programming model).
■ Why Study Computer Architecture?
■ To design faster, cheaper, smaller, more reliable
computer.
Computer Architecture
Computer Organization
■ In describing computers, a distinction is
often made between computer architecture
and computer organization.
■ Computer architecture refers to those
attributes of a system visible to a
programmer.
■ Computer architecture deals with:
■ What the computer does.
■ Instruction set architecture (ISA)
Computer Architecture
Computer Organization
■ In describing computers, a distinction is often
made between computer architecture and
computer organization.
■ Computer organization refers to the functional
units and their interconnections that realize the
architectural specifications.
■ Computer organization deals with:
■ How the computer does it.
■ Control signals, memory types, data paths, and the
actual circuitry.
The Five Classic Components of a
Computer
■ Input (mouse, keyboard, …)
■ Output (display, printer, …)
■ Memory
■ main (DRAM), cache (SRAM) Input
■ secondary (disk,
CD, DVD, …)
Outp
■ Datapath
Processor ut
■ Control Processor
(CPU)
Control
Memory
1001010010110
0010100101010
000
1111011101100
001
1001010010110
110
1001010010110
000
Datapath 1001010010110
000
000
History of the Development of
Computers
Moore’s Law
Growth of DRAM chip capacity over time
Computers
■ Desktop
■ Laptop
■ Embedded
■ Server
Embedded System: Embedding a
Computer
Digital Actuator (motor)
Output Analog
Analog
Sensor
Input Digital
CPU
Embedded Mem
Computer
• An embedded system typically includes a small computer into a larger device or
product.
• Example: ATM machine, microwave oven, washing machine.
• IoT system: embedded system with internet connectivity.
Computer Organization and
Architecture
■ Design of a computer
■ Design of the processor
■ Design of the instructions (Instruction Set Architecture, ISA)
■ Design of the memory
■ We will learn MIPS processor architecture.
■ Textbook: Computer Organization and Design -
Patterson & Hennessy
THANK
S
COD Ch. 1
Computer Abstractions and
Technology
Introduction
■ Rapidly changing field:
■ vacuum tube -> transistor -> IC -> VLSI
■ Number of transistors in a chip is doubling every 1.5 years:
■ memory capacity
■ processor speed (due to advances in technology and hardware
organization)
■ Things we’ll be learning:
■ how computers work, what’s a good design, what’s not
■ how to make them – yes, we will actually build working computers!!
■ issues affecting modern processors (e.g., caches, pipelines)
The Five Classic Components
of a Computer
■ Input (mouse, keyboard, …)
■ Output (display, printer, …)
■ Memory Input
■ main (DRAM), cache (SRAM)
■ secondary (disk,
CD, DVD, …) Outpu
■ Datapath Processor t
Processor
■ Control (CPU)
Control
Memory
10010100101100
00101001010100
00
01
11110111011001
10
10010100101100
00
10010100101100
Datapath 00
10010100101100
00
Our Primary Focus
■ The processor (CPU)…
■ Datapath: functional blocks and interconnections
between them
■ Control: control signals
■ ALU control
■ Memory R/W
■ MUX selections
Abstraction
Compiler and assembler are hiding the
low level details from the programmer.
A translation hierarchy for C code
A translation hierarchy for C code
• A high-level-language program is first compiled into an
assembly language program and then assembled into an
object module in machine language.
• The linker combines multiple modules with library
routines to resolve all references.
• The loader then places the machine code into the
proper memory locations for execution by the processor.
Instruction
Input data
Processor Output data
Instructions
■ An instruction is a collection of bits that a
computer understands.
The Instruction Set
Interface between hardware and low-level software.
software
instruction set
hardware
Instruction Set Architecture
■ Set of instructions understood by an architecture.
■ Interface between hardware and low-level software.
■ Advantage: allows different implementations of the same
architecture.
■ Modern instruction set architectures:
■ 80x86, PowerPC, DEC Alpha, MIPS, SPARC, HP
What is Computer Architecture?
Easy Answer
Computer Architecture =
Instruction Set Architecture +
Machine Organization (datapath & cotrol)
Instruction Set Architecture
■ RISC (Reduced Instruction Set Computing)
■ Simple, fixed-length instructions
■ ARM, MIPS, PowerPC, RISC-V
■ CISC (Complex Instruction Set Computing)
■ Complex, variable-length instructions
■ Intel x86, AMD, IBM System/360
Driving Forces in Computer Architecture
Technology Programming
Languages
Applications
Computer
Architecture
Operating
Systems
History
Review
MUX/Multiplexer
selector
I0 0 S
input 2 to 1 MUX output
I1 1
0 1
I0 0 S I0 0 S
I0 I1
I1 1 I1 1
2 to 1 MUX 2 to 1 MUX
Decoder
Y0
Y1
Decoder
X0
.
Input: n . Output: 2n
X1
.
X2
Y7
At a time one output line high (1).
Decoder
Y0 1
Decoder
0 X0 Y1 0
# input: 2 # output: 4
Y2 0
0 X1
Y3 0
At a time one output line high (1).
Decoder
Y0 0
Decoder
1 X0 Y1 1
Y2 0
0 X1
Y3 0
At a time one output line high (1).
Decoder
Y0 0
Decoder
0 X0 Y1 0
Y2 1
1 X1
Y3 0
At a time one output line high (1).
Decoder
Y0 0
Decoder
1 X0 Y1 0
Y2 0
1 X1
Y3 1
At a time one output line high (1).
Clock Signal
■ Square wave (voltage)
■ Frequency, f=1/T
1 clk cycle
5V
0V
Period (T)
time (t)
D Flip Flop
Value after
low to high clock transition
D Q D Q(t) Q(t+1)
0 0 0
CLK 0 1 0
1 0 1
1 1 1
Q(t+1)=D
t t+1
Values of Q0, Q1, Q2 at t1, t2
Q0 Q1 Q2
1 D Q D Q D Q
CP
DFF DFF DFF
CP:
t0 t1 Time Q0 Q1 Q2
t2
t0 0 0 0
t1
t2
Values of Q0, Q1, Q2 at t1, t2
0 0 0
Q0 Q1 Q2
0 1
1 D Q D Q D Q
CP
DFF DFF DFF
CP:
Time Q0 Q1 Q2
t0 t1 t2 t0 0 0 0
t1 1 0 1
t2
Values of Q0, Q1, Q2 at t1, t2
1 0 1
Q0 Q1 Q2
1 1
1 D Q D Q D Q
CP
DFF DFF DFF
CP:
Time Q0 Q1 Q2
t0 t1 t2 t0 0 0 0
t1 1 0 1
t2 1 1 1
Digital Circuit: Register
• Registers are designed based on Flip-Flops
• Stores 8/16/32 bits
Input Register Output (current data)
CLK
Chapter 7 <40>
THANK
S
