J277 Section 1 Systems Architecture, Memory and Storage

CPU

The central processing unit is the primary component of a computer that performs most of the processing inside the system. It executes instructions from programs and manages the operations of other hardware components.

Input Device

A hardware component used to enter data and control signals into a computer system, such as a keyboard or mouse.

Output Device

A hardware component that conveys information from a computer to the user, such as a monitor or printer.

Storage Device

A hardware component that is used to store data and information in a computer system, such as a hard drive or solid-state drive.

Memory

A component that stores data temporarily for quick access by the CPU, including RAM and cache.

Secondary Storage

A type of storage that retains data long-term, even when the computer is powered off, including devices like hard drives, SSDs, and optical disks.

Cache

A small, high-speed memory component that stores frequently accessed data and instructions to speed up processing by the CPU. Level 1 is closest to the CPU, while Level 2 is slightly larger and slower.

FDE cycle

The process by which the CPU fetches, decodes, and executes instructions in a sequence to perform tasks.

Fetch

The first stage of the FDE cycle where the CPU retrieves an instruction from memory.

Decode

The stage in the FDE cycle where the CPU interprets the fetched instruction to determine what action to perform next.

Execute

The final stage of the FDE cycle where the CPU carries out the instruction that has been decoded, resulting in an action or operation.

Control Unit

The component of the CPU that directs the operation of the processor and manages the execution of instructions by coordinating between the CPU and other components.

ALU

A component of the CPU that performs arithmetic and logical operations on the data processed by the system.

Accumulator

A register in the CPU that temporarily holds data and results of arithmetic and logical operations performed by the ALU.

Von Neumann Architecture

A computer design model that describes a system where the CPU, memory, and input/output devices are interconnected. It utilizes a single memory space for both data and instructions, allowing for efficient processing.

Registers

Small, fast storage locations within the CPU that hold data, instructions, and addresses temporarily during processing.

MAR

(Memory Address Register) holds the memory location of data that needs to be accessed or stored.

Program Counter

A CPU register that contains the address of the next instruction to be executed in a program. It increments after each instruction fetch.

MDR

(Memory Data Register) holds the actual data being transferred to or from the memory location specified by the MAR.

Logical Operations

Operations that manipulate binary data to perform tasks such as AND, OR, and NOT. These operations are fundamental in computing for decision-making and data processing.

Arithmetic Operations

Mathematical calculations performed on numerical data, including addition, subtraction, multiplication, and division. These operations are essential for processing numerical information in computing.

Shift Operations

A type of logical operation that moves bits in a binary number left or right, effectively multiplying or dividing the number by powers of two.

Clock Speed

The rate at which a CPU executes instructions, typically measured in gigahertz (GHz). Higher clock speeds indicate faster processing capabilities.

Cores

The individual processing units within a CPU that can execute instructions independently, improving performance and multitasking capabilities.

CPU Performance Factors

Factors that affect the overall efficiency and speed of a CPU, including clock speed, number of cores, cache size, and architecture.

RAM

(Random Access Memory) is a type of volatile memory that temporarily stores data and instructions for the CPU, allowing for quick access and efficient processing during active tasks.

ROM

A type of non-volatile memory that retains data even when powered off, commonly used to store firmware and system software (BIOS). It is crucial for booting up the computer and can be read but not easily written to.

Embedded System

A specialized computing system designed to perform dedicated functions within larger mechanical or electrical systems, often with real-time computing constraints. These systems are typically integrated into devices like appliances, automobiles, and medical equipment, and are optimized for specific tasks.

Parallel processing

A method of computation in which multiple processors or cores execute tasks simultaneously, improving performance and efficiency for complex calculations or large data sets.

Features of an Embedded System

Typically includes real-time operation, resource constraints, and specific functionality tailored to a particular application. They often have limited operating systems, minimal user interfaces and are designed for efficiency in power and processing.

Virtual Memory

A memory management capability that allows a computer to use hard drive space as additional RAM, enabling the execution of larger applications than the physical memory alone would allow. This process enhances multitasking and overall system performance by swapping data between RAM and disk storage as needed but can be slow compared to accessing physical memory directly.

Volatile

Refers to a type of computer memory that requires power to maintain the stored information. When power is lost, all data in volatile memory is erased, making it suitable for temporary data storage during processing.

Non-volatile

Refers to a type of computer memory that retains stored information even when power is lost. This makes it suitable for long-term data storage, such as in hard drives and flash memory.

Bootstrap Loader

A small program stored in ROM that initializes the operating system during the startup process of a computer. It loads the main operating system into memory and prepares the system for use.

BIOS

A firmware interface that initializes hardware during the booting process and provides runtime services for operating systems.

Factors affecting choice of storage

Includes speed, capacity, cost, portability, reliability and durability, which influence the selection of appropriate storage solutions based on user needs and system requirements.

Magnetic storage

A type of storage that uses magnetic media to read and write data, commonly found in hard disk drives (HDDs) and magnetic tapes. It is characterized by its ability to store large amounts of data at a relatively low cost.

Optical Storage

A type of storage that uses laser technology to read and write data on optical discs such as CDs, DVDs, and Blu-rays. It is known for its portability and capacity to store data in a durable format.

Solid State Storage

A type of storage that uses flash memory to store data, known for its speed, reliability, and durability such as a Solid State Disk, USB Memory Stick or SD Card. Unlike magnetic storage, it has no moving parts, making it more resistant to physical shock.