1.1- Processor characteristics, Input/Output and Storage devices Flashcards
What is a heatsink?
The CPU’s own dedicated fan that serves the sole purpose of keeping it cool.
What is the CPU?
The circuitry/ hardware that controls the manipulation / processing of data
What is the ALU
The dedicated register that performs the arithmetic, logical, and shift operations on the data
What is the CU?
The dedicated register coordinating the activities of the CPU via control signals
What is a register?
Quick, small stores of data within the CPU
What is Von Neumann Architecture?
The Von Neumann architecture used the idea of storing program instructions and data in main memory and moving them between memory and the processor
It breaks computer systems down into 3 major components:
Main Memory
CPU
Input/output
Explain the role of the memory characteristic in the Von Neumann Architecture model
Instructions to be executed are stored in the memory (alongside the data) as binary values
This is the Stored Program Concept
What model contrasts with Von Neumann architecture?
The Harvard Model
What are the features of the Harvard model?
Harvard architecture keeps instructions and data in separate memories.
The processor accesses these memories using separate data and address buses
Where is the Harvard model usually featured?
In embedded systems and microcontroller devices
Explain the role of the CPU characteristic in the Von Neumann Architecture model
Instructions are executed sequentially
Meaning one Instruction at a time is fetched from Memory and passed to the CPU
What is the role of a system clock in a computer?
It provides a series of (on/off) timing signals to synchronise the operations of processor components (circuits)
How does clock speed work?
CPUs are designed to operate at a specific frequency
The system clock is raised to this rate by the processor
This provides the clock speed (Hz)
The CPU needs a certain amount of clock cycles per instruction
What factors effect CPU performance?
Instruction pipelining
Number of cores
Cache size
Clock speed
What is instruction pipelining?
It allows a processor to execute multiple instructions simultaneously by breaking them down into smaller
What is a prerequisite for pipelining?
In order to apply pipelining to a task, that task needs to be able to be broken down into subtasks that can be handled independently.
Why might some systems prefer a Harvard Architecture system?
Both memories can be accessed simultaneously. This minimises the issue of keeping the processor waiting while loading or saving data into memory
Why might some systems prefer a Von Neumann Architecture system?
It enables a more flexible use of the main memory, which allows the processor to run a variety of programs that are not known in advance.
What are CISC and RISC?
RISC and CISC are types of processors with different instruction set architectures (ISAs).
What is a feature of RISCs?
Their instruction set consists of simple commands designed to take the same time to execute:
one instruction is carried out per system clock cycle.
What is a feature of CISCs?
Designed to execute complex instructions so…
Instructions can take several clock cycles to be executed
What are GPUs
GPUs are processors designed for parallel processing, which can improve the performance of video- or graphic-intensive applications.
What is an advantage of a GPU?
It frees up the main processor to handle other tasks. Graphics cards contain their own sets of RAM as well as a processor.
How do you choose an appropriate method for data input?
Cost
Speed
Accuracy
Reliability
What is biometric spoofing?
Biometric spoofing is a term used to describe a method of fooling biometric scanners
What’s a biometric?
A biometric is a physical characteristic such as fingerprints
What are sensors
There is a wide range of control systems in which sensors act as analogue inputs.
The analogue signal is converted to digital form (for processing) by an analogue to digital converter (ADC).
What does RFID stand for?
radio frequency identification
What does RFID do?
Allows data to be transmitted wirelessly over radio waves.
What are the three main types of storage
Optical
Solid State
Magnetic
Define secondary storage.
Secondary storage is storage that provides persistent (permanent) storage for data files
It’s non volatile which means
that it stays after being turned off
What are the typical capacities of secondary storage?
Magnetic hard disk 1TB Max.
Solid-state disk 256GB
CD is 700MB
How do Hard disks read/write data?
Concentric tracks are created on a HDD
Disk spins at high speed (up to 7200rpm)
Spinning platters are read by drive heads
Data is read/written as a sector moves under the head
Why does fragmentation occur?
Fragmentation occurs when there is insufficient contiguous space to store the file.
What is an SSD?
An SSD is an electronic device that uses flash memory, and has no moving parts.
What are features of optical storage?
It is read-only, recordable and rewritable
What is virtual memory?
Part of the hard drive used as an extension to the RAM
What are actuators?
Motors that are used in conjunction with sensors to control a mechanism
What’s a barcode?
A barcode is a means of representing data in a machine-readable form.
Traditional barcodes represent data by using a set of parallel lines of varied width and spacing.
How do QR scanners work?
QR code scanners do not use lasers; the codes are captured and read by taking an image of the QR code
What is the most common type of barcode readers?
Laser scanner
What are the two different types of display devices?
LCD displays
LED displays
OLED screens
What are the most common displays?
LCD
What are the benefits of LED displays?
LED technology uses less power than LCD
It is cheaper and more environmentally friendly to run LED displays.
What are the advantages of OLEDs?
OLEDs do not require a backlight, but are instead activated using an electric current.
They use a thin film of transparent plastic for the screen- brighter and more flexible
What are the 3 printer types?
Inkjet
Laser
Dot matrix
What are inkjet printers?
Non-impact printers that use liquid ink to produce black-and-white or colour prints
Features of inkjet printers
low upfront cost
superior colour production and paper handling capabilities.
Features of laser printers
They print a whole page at a time, so are usually faster than inkjet printers.
Uses powdered ink that is cheaper than liquid ink, and lasts longer.
Quality is poor for photo-quality images
What does the width of the address bus determine?
The number of bits that can be used to form an address of a memory location.
if the width is n
Then there are 2^n locations accessible for the processor
