Von Neumann architecture describe the interaction of CPU with peripheral devices describe the purpose of CPU components, system bus and main memory

Von Neumann architecture

Video worksheet (download)

Memory and the stored program concept

Computers as we know them were first built in the 1940s, and two of the early pioneers were Alan Turing and John von Neumann. The von Neumann architecture specifies the basec components of the computer and processor in which a shared memory and bus is used for both data and instructions.

The stored program concept:

  • A program must be resident in main memory to be executed.
  • Machine code instructions are fetched, one after another, from main memory in sequence and are executed, one at a time, in the processor.

Virtually all computers today are built on this principle, and so the general structure as shown in the figure below is sometimes referred to as the von Neumann machine.

How data is stored in computer memory?

  • All data and instructions are stored in the Main Memory.
  • Data stored in memory in binary code.

Central Processing Unit (CPU)

Central Processing Unit is a brain of computer.

Control Unit is the part of the processor that manages the execution of instructions.

ALU is the part of the processor that processes and manipulates data, carries out two types operation – arithmetic (+,-,*,/) and logic (AND, OR, NOT, etc).

Registers - the section of high speed memory within the CPU that stores data to be processed.

The scheme of interaction of computer parts

Main memory – stores data and instructions that will be used by the processor.


Name three internal components of a processor.
Explain the stored program concept.

Exam questions:

Describe the Von Neumann model of computer architecture. (5 marks)
  • The computer has memory that can hold data and the program (1) (nowadays called RAM).
  • The control unit manages the process of moving the data (1) and program between memory and storage - in the VN design this is called the "accumulator" (1).
  • The ALU is the calculator in the model (1). It also operates relative calculations such as "less than".
  • The bus indicates the flow of data (1) between each component and is shown as arrows om the diagram.


Ex.1 (Author: Litvinova Olga - CS teacher of NIS Pavlodar)

Ex.2 (Author: Litvinova Olga - CS teacher of NIS Pavlodar)

Next topic System bus


Категория: System architecture | Добавил: bzfar77 (06.09.2020)
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