ch4 Flashcards
features of the Von Neumann
architecture
1- has a central processing unit (CPU or processor)
2- a processor that can access data directly
3- computer memories that could store programs as well as data
4- stored programs made up of instructions that could be executed in sequential order
main components of the processor
1- arithmetic logic unit
2- control unit
3- system clock
4- immediate access store
Arithmetic logic unit (ALU)
component of a processor that carries out all arithmetic and logical operations
accumulator
temporary general purpose register which stores numerical values at any part of a given operation
job of control unit
Ensures the execution of instructions in the correct sequence. The CU ensures synchronisation of data flow and program instructions throughout the computer.
job of system clock
A system clock is used to produce timing signals on the control bus to ensure this vital synchronisation takes place
immediate access store
hold data temporirly that the cpu needs to access
register
temporary component in the processor that can be general or specific in its use that holds data and instructions as part of the fetch and execute cycle
job of general purpose register
holds data that needs to be frequently accessed by the cpu or by the programmer when accessing the cpu directly
job of specific purpose register
has a specific function within the cpu and holds the program state
index register
used when carrying out index addressing operations
status register
used when an instruction needs some sort of arithmetic or logical processing
address bus
carries the addresses throughout the computer (unidirectional bus)
data bus
carries data from from processor to memory (vise versa) and input/output devices
(bidirectional)
control bus
carries signals from control unit to other components of the computer (bidirectional)