Modes of Addressing Memory

Programs can be coded to use direct types of memory address. This allows program instructions to access high numbers of memory locations for storing and retrieving data and instructions.

Immediate addressing

In immediate addressing, the opcode is the actual value to be used.
The binary opcode of 00000101 would give the value of 5 to the CPU to work with if we used the immediate addressing mode.
This is a way to give the data directly to the processor so it doesn’t need to access another memory location.

Direct addressing

In direct addressing, the opcode is the address for the memory location where the data can be found.
The instruction contains the memory address of the operand.
The value is not given directly. The CPU has to retrieve the value from the given memory location.
In Little Man Computer, this is the only type of addressing available.

Indirect addressing

In indirect addressing, the opcode is the location of the value to be used.
The instruction contains the address of a memory location that holds the actual address of the operand.
This is usually a register.
By using indirect addressing, the CPU can access a significantly higher number of addressable locations.

Indexed addressing

In indexed addressing, the opcode is one value that is added together with a value stored in the index register to give the location of the data to be used.
The index register value is a constant value that indicates the first memory location for an array of data items.
By adding the index register and the opcode value together, you get the address of the next location to get data from.

1Components of a Computer

1.1Structure & Function of the Processor

1.1.1Structure of the CPU

1.1.2Fetch, Decode, Execute Cycle

1.1.3Factors Affecting CPU Performance

1.1.4CPU Architecture

1.2Types of Processors

1.2.1CISC & RISC

1.2.2Multicore & Parallel Cores

1.3Input, Output & Storage

1.3.1Computer Systems

1.3.2Magnetic Storage

1.3.3Optical Storage

1.3.4Types of Optical Storage

1.3.5Types of Memory

1.3.6Flash Memory

1.3.7Virtual Memory

2Software & Software Development

3Exchanging Data

4Data Types, Data Structures & Algorithms

4.1Data Types

4.1.1Data Types

4.1.2Arrays & Strings

4.1.3Representing Numbers

4.1.4Binary Arithmetic

4.1.5Hexadecimal

4.1.6Converting Binary Numbers

4.1.7Floating Points in Binary

4.1.8Floating Point Arithmetic

4.1.9Bitwise Manipulation

4.1.10Character Sets

4.2Data Structures

4.2.1Arrays, Linked Lists & Queues

4.2.2Graphs, Hash Tables & Stacks

4.2.3Trees

4.3Boolean Algebra

4.3.1Computational Logic

4.3.2Boolean Logic

4.3.3Karnaugh Maps

4.3.4Boolean Identities

4.3.5Flip Flops & Adder Circuits

5Legal, Moral, Cultural & Ethical Issues

5.1Computing Related Legislation

5.1.1Data Protection Act (1998)

5.1.2Computer Misuse Act (1990)

5.1.3Copyright Designs and Patents Act (1988)

5.1.4Regulation of Investigatory Powers Act (2000)

5.2Moral & Ethical Issues

5.2.1Online Activity Tracking

5.2.2Censorship

5.2.3Cultural Issues

5.2.4Environmental Issues

5.2.5Layout, Colour Paradigms & Character Sets

6Elements of Computational Thinking

6.1Thinking Abstractly

6.1.1Abstraction

6.2Thinking Procedurally

6.2.1Decomposition

6.3Thinking Logically

6.3.1Pseudocode & Flow Diagrams

7Problem Solving & Programming

7.1Programming Techniques

7.1.1Programming Fundamentals

7.1.2Modularity

7.2Programming Construction

7.2.1Integrated Development Environments

7.2.2Testing

8Algorithms

8.1Algorithms

8.1.1Interpreting, Correcting & Completing Algorithm

8.1.2Sort Algorithms

8.1.3Insertion & Merge Sort

8.1.4Search Algorithms

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