Paulius M thinks this is interesting: periodic refresh of the circuits From Chapter 4 Microprocessors from CompTIA A+ Certification All-in-One Exam Guide, Ninth Edition (Exams 220-901 & 220-902), 9th Edition by Mike Meyers Publisher: McGraw-Hill Released: January 2016 Note A bit more details would be nice Share this highlight http://www.safaribooksonline.com/a/comptia-a-certification/682187/ Twitter Facebook Google Plus Email Get Instant Access Now Start a Free Trial Have an account? Sign in. Minimise Unlock the rest of this book and 30,000 other books and videos By clicking this box, you confirm that you have read and agree to the terms and conditions of our Membership Agreement, and you understand that when your trial period ends, you will be required to provide billing information if you wish to continue using the service. Unlock the rest of this book Start a Free 10-Day Trial loading Learn about Safari for Business Have an account? Sign in.