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.
From celebrity tweets to hosting live Twitter chats, our favorite Twitter tips will have you tweeting like a pro in no time. Read More »Interesting Times: Transformation in the IT Channel
Business transformation will remain the buzzword of the moment as channel firms continue to assess the direction of their companies in the age of... Read More »11 Tips to Boost Your Wi-Fi Signal
It's not just your lawnmower and household tools that your neighbor won't return. Our top picks include everything from updating device firmware... Read More »
From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »Network Fundamentals Study Guide
A network is a group of two or more computer systems or devices, linked together to share resources, exchange files and electronic communications.... Read More »Computer Architecture Study Guide
This Webopedia study guide describes the different parts of a computer system and their relations. Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »