Clock speed measures how many cycles the CPU does per second. It is measured in hertz
Cache is memory on the CPU which is faster than RAM but slower than registers. It is for storing a small amount of fast accessed memory
The arithmetic logic unit (ALU) performs arithmetic and logic operations
Registers
Program counter - holds the address of the next instruction to be fetched from memory, increases the value by one and is incremented after the next instruction is fetched
Memory address register - holds the address of the current instruction that is to be fetched from memory
Memory data register - holds the contents found at the address held in the MAR
Accumulator - holds data for the arithmetic operations
RAM is memory that can be read and changed in any order, used for storing data and machine code currently in use and its memory is wiped upon turning off - it's volatile
ROM - read only memory, meaning it can be read from in any order but not written to
Virtual memory - memory that is taken from the hard drive to store data that the RAM can't from it being full
An embedded system is a computer system which is built into another device
RAM can hold clipboard data
When the RAM is no longer full, old instructions that are needed are swapped back
Computers need secondarystorage because RAM is volatile, meaning it loses its contents when the computer is switched off.
The purpose of the CPU is to processdata and instructions by constantly repeating the fetch,executecycle
A register is a small amount of fast access memory inside the processor where data or instructions can be stored temporarily
Control unit
Sends out control signals to other parts of the CPU
Executes program instructions following the fetch, decode, execute cycle
Made up of two parts:
The clock - coordinates the CPU's activity
The decoder - decodes program instructions
The main factors which affect CPU performance are:
Clock speed
Cache size
Number of cores
Why does cache size affect the performance of the CPU?
Data is transferred faster
Which makes the CPU more efficient
It is faster to transfer to and from cache than to and from RAM
The three common types of secondary storage are:
Magnetic
Optical
Solidstate
Characteristics to consider when choosing a secondary storage device:
Capacity / size / storage
Speed
Durability
Cost
Reliability
Portability
An output device is a hardware device used to receive data or information from a computer system
Which register always holds the address of the next instruction?
Program Counter
What is the name of the component that connects the processor to main memory?
System bus
In the fetch-decode-execute cycle, the controlunit breaks down the instruction
An advantage of harddisk over solid state memory is that before it fails, you get detectable anomalies
Magneticstorage is secondary storage that uses magnetic fields to magnetise spinning metal disks to store data.
An example is a hard disk drive or a floppy disk
The 4 registers in the CPU are:
ProgramCounter
Memory AddressRegister
Memory DataRegister
Accumulator
Registers are tiny areas of extremely fast memory located in the CPU that are designed for a specific purpose, where data or control information is stored temporarily to enable the fetch-decode-execute cycle to operate
A core is a processingunit within the CPU
Optical storage makes use of a laser to shine and reflect light to read the data stored. Examples include: CDs. DVDs.
Virtual memory is needed because the computer cannot multi-task when it runs out of memory.Virtualmemory allows the system to use a portion of secondary storage as if it were additional RAM, enabling the computer to handle more tasks simultaneously even when the physical RAM is fully utilized
The purpose of RAM is to be. a temporary store for instructions and data
The type of storage of hard disk is secondary storage
Hard disk drives are cheaper than solidstate drives
The purpose of the programcounter is to hold the address of the next instruction
RAM is primary storage
ROM is primary storage
Cache is primary storage
Without primarystorage, the computer wouldn't be able to start up or work
Secondarystorage stores the operating system of the device