4.1 Central processing unit (CPU) architecture Flashcards
Von Neumann architecture
computer architecture which introduced the concept of the stored program in the 1940s
Arithmetic logic unit (ALU)
component in the processor which carries out all arithmetic and logical operations
Control unit
ensures synchronisation of data flow and programs thoughout the computer by sending out control signals along the control bus
System clock
produces timing signals on the control bus to ensure synchronisation takes place
Immediate access store (IAS)
holds all data and programs needed to be accessed by the control unit
Accumulator
temporary general purpose register which stores numerical values at any part of a given operation
Register
temporary component in the processor which can be general or specific in its use that holds data or instructions as part of the fetch-execute cycle
Status register
used when an instruction requires some form of arithmetic or logical processing
Flag
indicates the status of a bit in the status register
for example, N = 1 which jndicates the result of an addition gives a negative value
Address bus
carries the addresses throughout the computer system
Data bus
allows data to be carried from processor to memory (and vice versa) or to and from input/output devices
Control bus
carries signals from control unit to all other computer components
Unidirectional
used to describe a bus in which bots can travel in one direction only
Bidirectional
used to describe a bus in which bots can travel in both directions
Word
group of bits used by a computer to represent a single unit
Clock cycle
clock speeds are measured in terms of GHz (this is the vibrational frequency of the clock which sends out pulses along the control bus)
Overclocking
checking the clock speed of a system clock to a value higher than the factory/recommended setting
BIOS
basic input/output system
Cache memory
a high speed auxiliary memory which permits high speed data transfer and retrieval
Core
a unit made up of ALU, control unit and registers which is part of a CPU
a CPU may contain multiple cores
Port
external connection to a computer which allows it to communicate with various peripheral devices
a number of different port technologies exist
Universal serial bus (USB)
a type of port connecting devices to a computer
Asynchronous serial data transmission
serial refers to a single wire being used to transmit bits of data one after the other
asynchronous refers to a sender using its own clock/timer device rather than sharing the same clock/timer with the recipient device
High-definition multimedia interface (HDMI)
type of port connecting devices to a computer
