Browse Prior Art Database

A Means To Reliably Determine The Steady State Of A USB Plug-and-Play System

IP.com Disclosure Number: IPCOM000014193D
Original Publication Date: 1999-Nov-01
Included in the Prior Art Database: 2003-Jun-19

Publishing Venue

IBM

Related People

Authors:
Phuc Do Dave A Williams Kumar Kori

Abstract

A Means To Reliably Determine The Steady State Of A USB Plug-and-Play System The dynamics of a hot plug or hot unplug event in a USB system makes it very hard to determine when the system reaches the steady state. This is especially true for a system with multiple keyboards due to the fact that they can switch modes. This switching modes makes it appear to the system that different physical devices have been hot plugged. The steady state needs to be accurately determined prior to assigning the device role and cluster. See "A Means to Reliably Distinguish Multiple Identical Devices" and "Method to Reliably Identify and Support Multiple USB Device Clusters" disclosures. The algorithm described can be used to reliably determine whether or not the system has reached steady state.