FCSCST1133Data Engineering Ecosystem

SCST1133 · Topic 01

CPU Instruction Cycle

Follow the fetch–decode–execute–store cycle that allows a processor to run instructions.

01Introduction to Computer and System
Processing

CPU Instruction Cycle

Follow the fetch–decode–execute–store cycle that allows a processor to run instructions.

CPU instruction cycle involving memory, registers, control unit and arithmetic logic unit
Figure 18. A processor repeatedly fetches, decodes, executes and stores instructions.

Four stages

Fetch

The next instruction is retrieved from memory, commonly through cache.

Decode

The control unit determines the required operation and operands.

Execute

The arithmetic logic unit or another execution unit performs the operation.

Store

The result is written to a register or memory for later use.

Why this matters

Clock speed alone does not determine performance. Cache, architecture, core count, memory latency and workload characteristics influence how efficiently instructions are completed.