Chapter 1: Computer Architecture

Computer Architecture #

Is a set of definitions for building a computer which contains:

• The Instruction Set Architecture (ISA)
• The Microarchitecture
• The Logic Design

Instruction Set Architecture (ISA) #

Defines the set of instructions and data that a computer can work with.

• Opcodes are symbols that can operate on data ie. add, sub, move.
• Operands are data that can be processed.
• Data Type the representation of a data ie. integer, float, char
• Addressing Mode identifies operands in a computer.

ISAs can also be classified into two categories, namely:

Complex Instruction Set Computer (RISC) #

An instruction set that performs multiple operations on a single instruction; can take several clock cycles to execute a single instruction.

Hardware-centric and provides lesser number of opcodes.

Reduce Instruction Set Computer (RISC) #

An instruction set that performs a single operation for a single instruction; a single instruction executes on a single clock cycle.

Software-centric and provides more opcodes.

Microarchitecture #

Defines the different high-level components that the ISA needs in order to be implemented.

Logic Design #

Defines the logic circuits that the Microarchitecture needs in order to be implemented.

Microprocessor #

The physical implementation of a computer.