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:
Jan. 24, 1984
Filed:
May. 05, 1980
Venu Chari, San Diego, CA (US);
Jack R Duke, San Marcos, CA (US);
Shimon Gersten, San Diego, CA (US);
NCR Corporation, Dayton, OH (US);
Abstract
A data processing system having a plurality of subsystems linked by a star coupler. The star coupler includes contention circuitry for controlling the star coupler so that at any given time no more than one selected subsystem can pass a message through the star coupler. The contention circuitry uses a conventional priority encode circuit to determine the selected one of the subsystems, so that the first message to be received from one of the subsystems is the message passed or, if two or more messages are received from subsystems simultaneously, the message from the subsystem having the highest relative priority established by the priority encode circuit is the message passed. In an embodiment showing an expanded star coupler, the contention circuitry has plural first level contention circuits and a second level contention circuit, each using a conventional priority encode circuit.