Computer Architecture and Operating Systems - Chapter 5

Vocabulary practice flashcards covering computer architecture, CPU operations, memory hierarchy, I/O transfer methods, and interrupt handling.

Computer Architecture

Refers to the overall design of the physical parts of a computer system, including what the main parts are, how they are physically connected, and how they work together.

Simplified Block Diagram of a Computer System

A structural diagram showing how the four basic components (CPU, Main Memory, Secondary Memory, and I/O Devices) communicate via an Interconnecting Bus.

Central Processing Unit (CPU)

The computing part of the computer responsible for program execution, fetching data from main memory, decoding it, executing instructions, and coordinating other system components.

Fetch-Decode-Execute Cycle Diagram

A four-step cycle where the CPU checks the PC register, retrieves the next instruction from RAM into a register, updates the PC register with the next address, and executes the instruction.

Program Counter (PC)

A special register inside the CPU that keeps track of the main memory address of the instruction that will be executed next.

CPU Registers

Internal storage spaces within the CPU used for frequently used data and operands, operating 10 to 100 times faster than main memory.

Primary Memory (RAM)

Volatile computer memory directly accessed by the processor without passing through I/O channels, temporarily holding running applications, the base operating system, and data during execution.

DDR RAM Key Notch Positions

Physical distinctions on RAM modules, such as DDR 2 and DDR 3, where the key notch position is altered to ensure proper socket alignment and compatibility.

Secondary Memory

Non-volatile, persistent auxiliary computer memory that is not directly accessed by the CPU, used to store programs and data permanently at a lower cost than main memory.

Hard Disk Platter Layout

The geometrical arrangement of a hard disk platter divided into concentric circular tracks, wedge-shaped sectors, and aligned cylinders.

Hard Disk Internal Anatomy

The physical internal assembly of a hard disk, including platters mounted on a spindle spinning at 7,200 to 10,000 rpm, read/write heads on actuator arms, and an actuator axis.

Track

A circular ring on the surface of a hard disk platter where data is recorded magnetically.

Sector

The smallest unit that can be read from or written to on a hard disk platter, containing a fixed number of bytes (usually 512 bytes).

Seek Time

The time required for the hard disk read/write head to move to the specific track where target data is located.

Rotational Latency

The time it takes for the desired sector on a hard disk platter to rotate directly beneath the read/write head.

Transfer Time

The time it takes to transfer data to or from the hard disk once the head is positioned over the correct track and sector.

Input and Output Devices Venn Diagram

A categorization mapping hardware into input devices, output devices, and dual-function I/O devices (such as touch screens, webcams, modems, and pendrives).

Program-Controlled I/O

An I/O operation method (also known as Polled, Synchronous, or Blocking I/O) where the CPU is directly involved for the entire duration and waits for completion.

Interrupt-Driven I/O

An asynchronous (non-blocking) I/O method where an I/O device sends an interrupt signal to inform the CPU when a requested operation has been completed.

Device Status Table

A table maintained by the operating system during interrupt-driven I/O that holds device status, request types, and a list of processes requesting device access.

Direct Memory Access (DMA)

A transfer mechanism used for high-speed I/O devices that allows data blocks (usually 64 KB) to transfer directly to main memory without passing through the CPU.

DMA Controller

A specialized chip responsible for managing Direct Memory Access transfers directly between high-speed I/O devices and main memory.

L1 and L2 Cache Memory Diagram

A diagram demonstrating Primary (L1) Cache integrated directly inside the CPU chip and Secondary (L2) Cache located on the processor package outside the CPU.

Cache Memory and Main Memory Flow

An architectural model showing how the CPU fetches instructions and data from cache memory while frequently used items are transferred from main memory into cache memory.

Hardware Interrupt

An interrupt request signal generated and sent by a physical I/O device to gain the attention of the CPU and operating system.

Trap (Exception)

A software-generated interrupt caused either by an error (e.g., division by zero or invalid memory access) or by a specific request from a user program for operating system services.

Interrupt Service Routine (ISR)

A specific handler routine, usually contained within device drivers, executed by the CPU to handle a particular device's interrupt request.