1.1.2

Von Neumann Architecture

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Von Neumann Architecture

All modern Central Processing Units (CPUs) are based on the Von Neumann architecture. The components of this architecture are:

Illustrative background for Arithmetic and Logic Unit (ALU)Illustrative background for Arithmetic and Logic Unit (ALU) ?? "content

Arithmetic and Logic Unit (ALU)

  • The ALU performs all of the arithmetic and logical operations of the CPU, including:
    • Addition and subtraction, multiplication and division.
    • Comparisons such as whether numbers are equal or if one is greater than another.
    • Boolean operations (e.g. AND, OR, NOT).
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Control Unit (CU)

  • The Control Unit transmits control signals to other components of the CPU.
  • The Control Unit follows the fetch-decode-execute cycle to execute program instructions.
  • There are two main components of the Control Unit:
    • The clock, which coordinates the CPU's activity.
    • The decoder, which decodes program instructions.
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Registers

  • Registers are tiny amounts of super-quick memory within the CPU.
    • They are used to hold information needed for the CPU to work.
    • Each register holds a specific piece of information.

Registers of the Central Processing Unit (CPU)

Registers that have a predetermined purpose in the central processing unit are known as special purpose registers.

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Program Counter (PC)

  • The PC holds the memory location address of the next instruction to be performed by the CPU.
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Accumulator (ACC)

  • The ACC holds the result of calculations and operations performed by the arithmetic logic unit (ALU).
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Memory Address Register (MAR)

  • The MAR holds the address of the location in memory where data is to be retrieved or stored.
Illustrative background for Memory Data Register (MDR)Illustrative background for Memory Data Register (MDR) ?? "content

Memory Data Register (MDR)

  • The MDR holds the data that has been retrieved from memory, or that is about to be stored in memory.

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1Computer Systems

1.1Systems Architecture

1.2Memory & Storage

1.3Computer Networks, Connections & Protocols

1.4Network Security

1.5Systems Software

1.6Ethical, Legal, Cultural & Environmental Concern

2Computational Thinking, Algorithms and Programming

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