The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 2001
Filed:
Nov. 10, 1998
Kenneth F. Gudan, Sunnyvale, CA (US);
Douglas M. Farrar, Los Altos, CA (US);
Christoph H. Krah, San Jose, CA (US);
Richard D. Cappels, Sr., San Jose, CA (US);
Apple Computer, Inc., Cupertino, CA (US);
Abstract
A power-up switch circuit in a peripheral device such as a keyboard is coupled to the main processing portion of a computer via an interface bus. The switch circuit together with bias and detection circuitry in the main processing portion allow non-intrusive use of a data communication line of the interface for controlling the supply of power to the main processing portion, without requiring a dedicated power-on wire between the peripheral device and the processing portion. A repeater circuit between the keyboard and the main processing portion causes a second signal to be sent through an upstream portion of the interface bus in response to receiving a first signal through a downstream portion of the bus, while the main processing portion is in low power mode. The repeater is also configured to not affect the interface bus when the main processing portion is in high power mode.