Fall 2025 (Abasyn University, Islamabad)

Sunday, 12 noon to 3 pm
Lecture # 1 (31 Aug 2025)
Dr. Adnan Masood
Mobile & WhatsApp: 0334-5344375
Email: am34029@yahoo.com
 PhD – Electrical Engg, 2006-09 (Cardiff University, UK)
 MS – Electrical Engg, 2001-03 (Drexel University, USA)
 BSc – Electrical Engg, 1990-93 (College of E&ME/ UET
Lhr)
 Teaching Experience
◦ Assistant Professor – 2009 to 2011, DMts, NUST CEME
◦ Associate Professor/ TVF – 2011 to 2016, DEE, NUST CEME
◦ TVF – 2018 & 2019, DMts, Air University, Islamabad
◦ TVF – 2023, DMts, NUST CEME
◦ TVF – 2024, Abasyn University, Islamabad
 Student Name
 BE Degree Discipline + University + Year of Graduation
 Occupation/ Job
Course Objectives
 This course will cover advanced concepts in computer
architecture. The emphasis is on modern processor design, and
will include multicore processor design.
Course Contents
 Introduction to Computer Architecture

 Fundamentals of Quantitative Design and Analysis

 Instruction Set Principles

 Memory Hierarchy Design

 Pipelining Concepts

 Instruction-Level Parallelism

 Data-Level Parallelism
 Computer Architecture: A Quantitative Approach, John L.
Hennessy and David L. Patterson (5th Edition)
 Computer Organization and Architecture: Designing for
Performance, William Stallings (10th Edition)

 Computer System Architecture, Morris Mano, (3rd Edition)

 Computer Organization and Design: The Hardware/ Software

Interface, David L. Patterson and John L. Hennessy (4th Edition)

 Computer Systems: Digital Design, Fundamentals of Computer

Architecture and Assembly Language, Ata Elahi
 https://www.spiceworks.com/tech/tech-

general/articles/what-is-computer-architecture/
 Computer architecture refers to the end-to-end structure of a
computer system that determines how its components interact with
each other in helping to execute the machine’s purpose (i.e.,
processing data), often avoiding any reference to the actual
technical implementation.

 It is the arrangement of the components that comprise a computer

system and the engine at the core of the processes that drive its
functioning. It specifies the machine interface for which
programming languages and associated processors are designed.
 Complex instruction set computer (CISC) and reduced instruction
set computer (RISC) are the two predominant approaches to the
architecture that influence how computer processors function.
 CISC processors have one processing unit, auxiliary memory, and a
tiny register set containing hundreds of unique commands. These
processors execute a task with a single instruction, making a
programmer’s work simpler since fewer lines of code are required
to complete the operation. This method utilizes less memory but
may need more time to execute instructions.
 A reassessment led to the creation of high-performance computers
based on the RISC architecture. The hardware is designed to be as
basic and swift as possible.
 Computer architecture allows a computer to compute, retain, and
retrieve information. This data can be digits in a spreadsheet, lines
of text in a file, dots of colour in an image, sound patterns, or the
status of a system such as a flash drive.
 Everything a system performs, from online surfing to printing,
involves the transmission and processing of numbers. A computer’s
architecture is merely a mathematical system intended to collect,
transmit, and interpret numbers.
 The working of a computer architecture begins with the bootup
process. Once the firmware is loaded, it can initialize the rest of the
computer architecture and ensure that it works seamlessly, i.e.,
helping the user retrieve, consume, and work on data.
 The main components of a computer architecture are the CPU,
memory, and peripherals. All these elements are linked by the
system bus, which comprises an address bus, a data bus, and a
control bus.
 Within this framework, the key components of computer
architecture are as follows:-
◦ Input unit and associated peripherals
◦ Output unit and associated peripherals
◦ Storage unit/memory
◦ Central processing unit (CPU)
◦ Operating system (OS)
◦ Buses
 The input unit provides external data sources to the computer
system. Therefore, it connects the external environment to the
computer. It receives information from input devices, translates it
to machine language, and then inserts it within the computer
system.

 The keyboard, mouse, or other input devices are the most often
utilized and have corresponding hardware drivers that allow them
to work in sync with the rest of the computer architecture.
 The output unit delivers the computer process’s results to the user.
A majority of the output data comprises music, graphics, or video. A
computer architecture’s output devices encompass the display,
printing unit, speakers, headphones, etc.
 To play an MP3 file, for instance, the system reads a number array
from the disc and into memory. The computer architecture
manipulates these numbers to convert compressed audio data to
uncompressed audio data and then outputs the resulting set of
numbers (uncompressed audio file) to the audio chips.
 The chip then makes it user-ready through the output unit and
associated peripherals.
 The storage unit contains numerous computer parts that are
employed to store data. It is typically separated into primary
storage and secondary storage.

Primary Storage Unit

 This component of the computer architecture is also referred to as
the main memory, as the CPU has direct access to it. Primary
memory is utilized for storing information and instructions during
program execution.
 Random access memory (RAM) and read-only memory (ROM) are
the two kinds of main memory.
 RAM supplies the necessary information straight to the CPU. It is a
temporary memory that stores data and instructions intermittently.

 ROM is a memory type that contains pre-installed instructions,

including firmware. This memory’s content is persistent and cannot
be modified. ROM is utilized to boot the machine upon initial
startup. The computer is now unaware of anything outside the ROM.
The chip instructs it on how to set up the computer architecture,
conduct a power-on self-test (POST), and finally locate the hard
drive so that the operating system can be launched.
Secondary Storage Unit
 Secondary or external storage is inaccessible directly to the CPU.
Before the CPU uses secondary storage data, it must be transferred
to the main storage.

 Secondary storage permanently retains vast amounts of data.

Examples include hard disk drives (HDDs), solid-state drives (SSDs),
compact disks (CDs), etc.
 The CPU includes registers, an arithmetic logic unit (ALU), and
control circuits, which interpret and execute assembly language
instructions.
 The CPU interacts with all the other parts of the computer
architecture to make sense of the data and deliver the necessary
output. A brief overview of the CPU’s sub-components is as below:
Registers
 These are high-speed and purpose-built temporary memory
devices. Rather than being referred to by their address, they are
accessed and modified directly by the CPU throughout execution.
Essentially, they contain data that the CPU is presently processing.
Registers contain information, commands, addresses, and
intermediate processing results.
Arithmetic Logic Unit (ALU)
 The ALU includes the electrical circuitry that performs any

arithmetic and logical processes on the supplied data. It is used to

execute all arithmetic (additions, subtractions, multiplication,
division) and logical (<, >, AND, OR, etc.) computations. Registers
are used by the ALU to retain the data being processed.
Control Unit
 The control unit collaborates with the computer’s input and output

devices. It instructs the computer to execute stored program

instructions via communication with the ALU and registers. The
control unit aims to arrange data and instruction processing.
 The operating system governs the computer’s functionality just
above firmware. It manages memory usage and regulates devices
such as the keyboard, mouse, display, and disc drives. The OS also
provides the user with an interface, allowing them to launch apps
and access data on the drive.

 Typically, the OS offers a set of tools for programs, allowing them to

access the screen, disc drives, and other elements of the computer’s
architecture.
 A bus is a tangible collection of signal lines with a linked purpose; a
good example is the universal serial bus (USB). Buses enable the
flow of electrical impulses between various components of a
computer’s design, transferring information from one system to
another.

 The size of a bus is the count of information-transferring signal

lines. A bus with a size of 8 bits, for instance, transports 8 data bits
in a parallel formation.