MODULE 3: COMPUTER SYSTEMS ORGANIZATION AND ARCHITECTURE

computer system

complex combination of hardware and software components designed to perform various tasks and operations by processing and manipulating data.

hardware and software

computer system is consist of both physical (______) and logical (____) elements.

scope of computer systems

is vast and encompasses a wide range of applications, from personal computers and smartphones to supercomputers, embedded systems, and cloud computing.

Computer systems

are used in various fields such as business, science, education, entertainment, and more.

HISTORICAL DEVELOPMENT AND EVOLUTION OF COMPUTERS

Computers have a rich history that dates back to ancient devices like the abacus. The development of modern computers can be divided into several key stages

MECHANICAL COMPUTERS

is a computer built from mechanical components such as levers and gears rather than electronic components.

MECHANICAL COMPUTERS

Charles Babbage's Analytical Engine

ELECTROMECHANICAL COMPUTERS

These machines combine electrical energy with mechanical movement to perform computations, often relying on components like rotating shafts, clutches, and relays.

ELECTROMECHANICAL COMPUTERS

IBM's Mark I

VACUUM TUBE COMPUTERS

Known as first-generation computers, vacuum tubes acted as the electronic switches and logic gates that form the basis of a computer's central processing unit (CPU).

VACUUM TUBE COMPUTERS

ENIAC

TRANSISTOR COMPUTERS

The second generation of electronic computers,utilizing individual transistors instead of bulky, unreliable, and heat-generating vacuum tubes.

TRANSISTOR COMPUTERS

UNIVAC

INTEGRATED CIRCUIT COMPUTERS

fundamental building blocks of modern computers, replacing the bulky and unreliable vacuum tubes of early computing and enabling the creation of smaller, faster, and more powerful devices.

INTEGRATED CIRCUIT COMPUTERS

Intel 4004

MICROCOMPUTERS

is a small, relatively inexpensive computer that uses a microprocessor as its central processing unit (CPU).

MICROCOMPUTERS

IBM PC

PERSONAL COMPUTERS

PCs are operated directly by an end user and can be used for a wide range of tasks, including word processing, internet browsing, and gaming.

PERSONAL COMPUTERS

Macintosh (Mac)

PERSONAL COMPUTERS

Windows PC

CENTRAL PROCESSING UNIT (CPU)

brain of the computer, responsible for executing instructions and performing calculations. It fetches data and instructions from memory and performs operations on them. (CMISMP)

Memory

stores data and instructions that the CPU needs for processing. 

RAM (Random Access Memory)

volatile and used for temporary storage.

ROM (Read-Only Memory)

stores essential firmware and software.

INPUT AND OUPUT (I/O) DEVICES

enable communication between the computer and the external world. Examples include keyboards, mouse, displays, printers, and network interfaces.

STORAGE DEVICES

store data for long-term use. Common storage devices include hard disk drives (HDDs), solid-state drives (SSDs), and optical drives.

MOTHERBOARD

main circuit board that houses the CPU, memory, and other essential components. It provides connections for all internal and external devices.

POWER SUPPLY

converts electrical energy from the outlet into the appropriate voltage and current required by the computer components.

Von Neumann architecture

proposed by John Von Neumann in the 1940s, is the foundational design for most modern computers. It consists of the following key components: (CMCAI)

John Von Neumann

Who proposed Von Neumann architecture?

CENTRAL PROCESSING UNIT (CPU)

fetches instructions and data from memory, decodes the instructions, executes them, and stores the results back in memory.

MEMORY

In the Von Neumann architecture, both program instructions and data are stored in the same memory. This memory is often referred to as RAM (Random Access Memory).

CONTROL UNIT

manages the execution of instructions, ensuring they are executed in the correct sequence.

ARITHMETIC LOGIC UNIT (ALU)

performs arithmetic and logical operations, such as addition, subtraction, mutiplication, and comparisons.

INPUT AND OUTPUT (I/O) DEVICES

Input and output devices allow data to be exchanged between the computer and the external world.

MEMORY HIERARCHY

structure that organizes various types of memory in a computer system based on their speed, cost, and capacity. 

MEMORY HIERARCHY

allows for efficient data storage and access, ensuring that frequently used data is readily available while balancing performance and cost considerations.

RANDOM ACCESS MEMORY (RAM)

Volatile memory used for temporarily storing data and program code that the CPU needs during operation. Provides fast access but is relatively limited in capacity compared to other forms of storage.

READ-ONLY MEMORY (ROM)

Non-volatile memory that stores firmware and essential system instructions that are permanently written during manufacturing. It cannot be modified by the user and retains data even when the power is off.

CACHE

A small, high-speed memory layer placed between the CPU and main memory (RAM). It stores frequently used data and instructions to reduce the CPU's access time to critical information.

SECONDARY STORAGE

Typically includes hard disk drives (HDDs) and solid-state drives (SSDs). Offers higher capacity than RAM but with slower access times. Used for long-term data storage, including the operating system, applications, and user files.

PROCESSOR DESIGN

• CPU (Central Processing Unit) Architecture and Components

• Pipelining and Superscalar Architectures

• Clock Cycles and Execution time

CENTRAL PROCESSING UNIT (CPU) ARCHITECTURE AND COMPONENTS

The CPU is the brain of a computer, responsible for executing instructions and performing calculations. Key components of a CPU include: (CARCC)

CONTROL UNIT

Manages instruction fetching, decoding, and execution.

ARITHMETIC LOGIC UNIT (ALU)

Performs arithmetic and logic operations.

REGISTERS

Small, high-speed memory for temporary data storage.

CACHE

Stores frequently accessed data for faster retrieval.

CLOCKED GENERATOR

Controls the timing of operations.

PIPELINING

Breaks down instruction execution into stages, allowing multiple instructions to overlap in their execution. This improves throughput and efficiency.

SUPERSCALAR

Executes multiple instructions simultaneously by having multiple execution units, like multiple ALUs. It enhances performance by exploiting instruction-level parallelism.

PARALLEL PROCESSING

The execution of multiple tasks simultaneously to improve performance.

MULTI-CORE PROCESSORS

CPUs with multiple processing cores on a single chip. Each core can execute instructions independently, enabling true parallel processing.

MULTI-CORE PROCESSORS

Benefits: Multi-core processors enhance multitasking, speed up parallelizable tasks, and reduce power consumption compared to increasing clock speeds.

CLOCK CYCLES

A CPU operates based on a clock signal, and each clock cycle corresponds to one basic operation.

CLOCK SPEED (CLOCK FREQUENCY)

Measured in Hertz (Hz), It indicates how many clock cycles occur per second.

EXECUTION TIME

The time taken to complete a task is a product of the number of clock cycles required and the duration of each cycle. Smaller clock cycles or more efficient instructions reduce execution time.

Execution Time = (Clock Cycles Required)(Duration of each cycle)

EXECUTION TIME FORMULA