3.1.2

Central Processing Unit (CPU)

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Central Processing Units

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 such as AND, OR and NOT.
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Control Unit (CU)

  • Sends out control signals to other parts of the CPU.
  • Executes program instructions by following the fetch-decode-execute cycle.
  • Made up of two key parts:
    • The clock - coordinates the CPU's activity.
    • The decoder - decodes program instructions.
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Registers and Cache

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

Jump to other topics

1Computational Thinking & Algorithms

1.1Computational Thinking

1.1.1Abstraction Thinking

1.1.2Decomposition Thinking

1.1.3Algorithmic Thinking

1.2Algorithms

1.2.1Algorithms

1.2.2Pseudocode

1.2.3Flow Diagrams

1.2.4Logical Reasoning & Debugging

1.2.5Reading Algorithms

1.2.6Correcting Algorithms

1.2.7Complete the Algorithm

1.2.8Search Algorithms

1.2.9Linear Search

1.2.10Binary Search

1.2.11Sort Algorithms

1.2.12Bubble Sort

1.2.13Insertion Sort

1.2.14End of Topic Test - Algorithms

2Programming

2.1Programming Fundamentals

2.1.1Variables & Constants

2.1.2Comments

2.1.3Input & Output

2.1.4Arithmetic Operators

2.1.5Relational Operators

2.1.6Boolean Operators

2.1.7Sequence

2.1.8Selection

2.1.9Iteration

2.1.10Subroutines

2.1.11Scope

2.1.12Data Types

2.1.13Casting

2.1.14Arrays

2.1.152D Arrays

2.1.16Lists

2.1.172D Lists

2.1.18Strings

2.1.19Syntax Errors

2.1.20Logic Errors

2.1.21Runtime Errors

2.1.22End of Topic Test - Programming

2.2Designing Code

2.2.1Code

2.2.2Programs

2.2.3Writing Your Own Program

2.2.4Designing a ‘Basketball’ Game

2.2.5Turning an Algorithm into an App

2.2.6End of Topic Test - Designing Code

2.3Python

2.3.1Introduction to Python

2.3.2Input

2.3.3Output

2.3.4Casting

2.3.5Type Coercion

2.3.6Selection

2.3.7Iteration

2.3.8Files

2.3.9File Handling

2.3.10Identifiers

2.3.11Whitespace

2.3.12Comments

2.3.13Exceptions

3Hardware & Software

3.1Hardware

3.1.1Elements of Computer Systems

3.1.2Central Processing Unit (CPU)

3.1.3Registers of the Central Processing Unit (CPU)

3.1.4Factors Affecting CPU Performance

3.1.5Fetch-Decode-Execute Cycle

3.1.6Binary Systems

3.1.7Logic Circuits

3.1.8Boolean Logic

3.1.9End of Topic Test - Logic

3.2Software

3.2.1System Software

4Data

4.1Representing Data

4.1.1Binary

4.1.2Converting Binary & Hexadecimal

4.1.3Converting Denary & Hexadecimal

4.1.4Binary Arithmetic

4.1.5Representing Sound

4.1.6Representing Images

4.1.7Character Sets

4.1.8American Standard Code for Information Interchange

4.1.9Unicode

4.1.10End of Topic Test - Representation

5The Internet

5.1Networks

5.1.1Networks

5.1.2Geographical Classification of Networks

5.1.3What is the Internet?

5.1.4The World Wide Web

5.1.5Uniform Resource Locators (URLs)

5.1.6Web Hosting

5.1.7HTML

5.1.8Searching the World Wide Web

5.1.9Good Searching Tips

5.1.10Are You Looking at Reliable Information?

6Online Safety & Security

6.1Protecting Yourself Online

6.1.1Digital Footprints

6.1.2Leaving a Safe Online Footprint

6.1.3Online Safety

6.1.4Malware - Viruses

6.1.5Malware

6.1.6People Online

6.1.7Your Feelings

6.1.8Getting Help

6.2Computing and the Law

6.2.1Data Protection Act (1998)

6.2.2Computer Misuse Act (1990)

6.2.3Freedom of Information Act (2000)

6.2.4Plagiarism

6.2.5Copyright

6.2.6Copyright Designs and Patents Act (1988)

6.2.7Creative Commons Licensing

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Elements of Computer Systems

Registers of the Central Processing Unit (CPU)