Hardware Flashcards
Define CPU
The main component in a computer for processing data and instructions
Define Arithmetic Logic Unit (ALU)
The ALU performs all the mathematical calculations/logical operations in the CPU
Define registers
Fast access storage locations found on the CPU where data or control information is temporarily stored
Define Control Unit/ controller
A register that directs the flow of instructions and/or data and coordinates the other parts of the CPU. It generates clock ticks or controls the clock
Define Program Counter (PC)- Also known as the instruction address register (IAR)
A register that keeps track of the memory address of the instruction to be executed next
Define accumulator (ACC)
A temporary storage of data used in calculations
Define memory address register (MAR)
Stores the address that is currently being read or written
Define memory data register (MDR)
Stores instructions taken from RAM
Define current instruction register (CIR)
A temporary holding area for the instruction that has just been fetched from memory
Define memory
The temporary storage of currently running programs and data
Define Cache/Internal Memory
Incredibly fast, but very expensive, volatile memory used in the CPU. Contains unused data from the register. Data can go to RAM or back to register
Define clock
Regulates the number of FDE cycles that a CPU can carry out per second. Synchronises components
Define cores
The processing components within the CPU. Some CPUs have multiple cores which can work in parallel, sequentially, or can multitask
Define volatile
Stored data is lost when the power is interrupted or switched off
Define permanent
Stored data is kept when the power is interrupted or switched off
Von Neumann architecture
. CPU
____________________________
| ALU |
Input | Register Controller | Output
| |__________________________ | |
|__________________|__________________|
|
Memory
What is performance affected by?
Cache size
Clock speed
Number of cores
What does greater cache size result in?
Can store more data and instructions
It can provide instructions and data to the CPU at a much faster rate (than other system memories such as RAM)
What does greater clock speed result in?
The FDE cycle will run faster, resulting in more instructions being processed
What does a greater number of cores result in?
More instructions can be processed at the same time (performance may be affected, where one core is waiting on the result of another and therefore cannot carry out any more instructions)
Define RISC (reduced instruction set computer)
Carries out complex commands by breaking them down into simpler instructions
Define CISC (complex instruction set computer)
Can process a large number of complex instructions. This allows the processor to understand and carry out complex tasks with only a few instructions.
Advantages of RISC- 4 points
•Processes the simpler instructions quickly
•Less circuitry to decode and execute instructions
•Less power consumption
•Less heat being generated
Advantages of CISC
A CISC processor is able to process complex instructions, without having to break them down into many simpler instructions
Disadvantages of RISC
A RISC processor is unable to process complex instructions, and has to to break them down into many simpler instructions which takes time
Disadvantages of CISC (3)
• More circuitry to decode and execute instructions
• More power consumption
• More heat being generated
What do input devices do
Sends data to the computer system
What do output devices do
Receives and displays data from the computer system
Define Primary Storage
The main memory where everything is saved to
4 types of primary storage (in speed order)
Cache Memory
Read-Only Memory (ROM)
Random Access Memory (RAM)
Flash Memory
Which of the 4 primary storage types are permanent/volatile?
Volatile- Cache Memory
Permanent- Read-Only Memory (ROM)
Volatile- Random Access Memory (RAM)
Permanent- Flash Memory
Which primary storage can data be changed?
✅Cache Memory
❌Read-Only Memory (ROM)
✅Random Access Memory (RAM)
✅Flash Memory
Example use of Cache Memory
The temporary storage of frequently accessed data and instructions
Example use of Read-only Memory (ROM)
Storing programs such as the system BIOS
Example use of Random Access Memory (RAM)
Storing currently running programs and data
Example use of Flash Memory
Storing programs such as the system BIOS
Define secondary storage
the storage of data that is not accessed as frequently as the data in primary storage
Types of secondary storage
Optical
Magnetic
Solid State
How does optical storage work?
Laser beams are projected onto a disc and if light is reflected back, then data is read as 1. If light is not reflected back, data is read as 0.
How does magnetic storage work?
Data is stored on a magnetic medium (disk or tape) using a write-head and magnetic platter. The data can be read using the read-head
Features of solid state storage (3)
- Doesn’t have any moving parts
- Low power consumption
- High-speed access
4 types of secondary storage (in speed order)
Solid- Flash Drive
Solid- External Hard Drive
Optical- CD/DVD/Blu-ray Disk
Magnetic- Magnetic Tape
4 types of secondary storage (in durability order)
Solid- Flash Drive
Optical- CD/DVD/Blu-ray Disk
Magnetic- Magnetic Tape
Solid- External Hard Drive
Typical capacity of the 4 secondary storage
Flash Drive: 2GB-512GB
External Hard Drive: 320MB-8TB
CD/DVD/Blu-ray Disk: 650MB (CD)
9GB (DVD)
50GB (Blu-ray)
Magnetic Tape: 200GB-400GB
Suitability of Flash Drive
Moving relatively small files from work to home
Suitability of external hard drive
Backing up a home computer system
Suitability of discs
Storing multimedia files
Suitability of magnetic tape
Backing large commercial servers on multiple tapes
Specifications of an Integrated GPU (Graphics Processing Unit) (4)
- Uses the computer’s RAM
- Cheaper than installing a dedicated GPU
- Generates less heat and uses less power
- Perfect for general graphics processing, such as watching or editing videos, and word processing
Specifications of an Dedicated GPU (Graphics Processing Unit) (4)
- Has its own video memory
- Provides the best visual experience
- Used by graphic designers and gamers
- Uses more power and requires a good cooling system
Define sound card
Converts analogue input signals into digital data and reverses this process for output
Define motherboard
Main circuit board of the computer
Define embedded systems
A combination of software and hardware that performs a specific task unlike a general purpose computer that is designed to carry out multiple tasks
Data storage units
Bit - b - 1 bit
Nybble - - 4 bits
Byte - B - 8 bits
kilobyte - KB - 1024 bytes
Megabyte - MB - 1024 KB
Gigabyte, Terabyte, Exabyte, Zettabyte, Yottabyte
Harvard Architecture
. ALU
|
Instruction ______ Control _____ Data
Memory Unit Memory
|
I/O
(input/output)
Define Basic Input Output System (BIOS)
Contains basic code to control computer hardware
Start up sequence of a computer (6 steps)
- Boot up sequence begins
- CPU loads BIOS from ROM into RAM
- BIOS starts up monitor and keyboard
- BIOS checks computer is working
- Operating system loaded from secondary storage into RAM
- Operating system takes control from BIOS
Define buses
Transfers data to different parts of a computer
What are the three main types of buses
Address bus
Data bus
Control bus
Define address bus
When data is saved or loaded, the bus transfers the address of where the data is being sent
Define data bus
Transfers the data
Define control bus
Used by the controller to send signals to different parts of the computer
Define the fetch-decode-execute cycle (FDE)
The three steps to processing an instruction given by a currently running program
Define fetch in the FDE cycle
Takes address from memory and stores it in MAR
MDR gets instruction from RAM, and CIR copies the instruction
ALU adds one to the program counter so that it points at the next instruction.
Define decode in the FDE cycle
The control unit uses the instruction from the CIR and decodes it to determine the action that needs to be carried out.
Define execute in the FDE cycle
The actual actions that happen during the execution cycle depend on the instruction itself.
