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. 12, 1993
Filed:
Nov. 13, 1989
Charles J Roslund, Penn Hills Twp., PA (US);
Linda L Santoline, South Park, PA (US);
Albert W Crew, Pittsburgh, PA (US);
Gilbert W Remley, O'Hara Township, PA (US);
William D Ghrist, III, Pittsburgh, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
Updated images of messages are passed between asynchronous digital processors using dual port shared memory. In the basic form of the invention, three buffers in shared memory are assigned to each message. Where one of the processors is a controller for a data link channel carrying n messages, 2n+1 buffers are provided in free shared memory space with 2 buffers assigned to each message at all times and a common buffer serving as the third buffer for all of the messages. Where linked buffers in local memory of a controller processor receive message updates from a data highway, two buffers in shared memory are assigned to each message and a linked buffer in the controller local memory serves as the third buffer. The buffers containing the message updates are passed between processors by use of a buffer status array in shared memory. A semaphore lock in the array permits only one processor at a time to assign or release buffers.