The time period during which one instruction is fetched from memory and executed when a computer is given an instruction in machine language. There are typically four stages of an instruction cycle that the CPUcarries out:
- Fetch the instruction from memory. This step brings the instruction into the instruction register, a circuit that holds the instruction so that it can be decoded and executed.
- Decode the instruction.
- Read the effective address from memory if the instruction has an indirect address.
- Execute the instruction.
Steps 1 and 2 are called the fetch cycle and are the same for each instruction. Steps 3 and 4 are called the execute cycleand will change with each instruction.
The term refers to both the series of four steps and also the amount of time that it takes to carry out the four steps.
An instruction cycle also is called machine cycle.
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
The following facts and statistics capture the changing landscape of cloud computing and how service providers and customers are keeping up with... Read More »Facts about Computer Science: Education and Jobs
The following computer science facts and statistics provide a quick introduction to the changing trends in education and related careers. Read More »Texting & Chat Abbreviations
From A3 to ZZZ this guide lists 1,500 text message and online chat abbreviations to help you translate and understand today's texting lingo. Read More »
Learn about each of the five generations of computers and major technology developments that have led to the computing devices that we use... Read More »Computer Architecture Study Guide
Computer architecture provides an introduction to system design basics for most computer science students. Read More »Network Fundamentals Study Guide
Networking fundamentals teaches the building blocks of modern network design. Learn different types of networks, concepts, architecture and... Read More »