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:
Nov. 12, 1996
Filed:
Oct. 25, 1994
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
In a disk storage system having dual controllers and mirrored memory therebetween, the mirrored memory is used to establish a robust communication path between the controllers to monitor and coordinate their activities. A reserved portion of the memory in each controller is designated as a messaging mailbox which is read and written by the owning controller but only read by the remote controller. The communication protocol between the controllers is tightly coupled to insure proper messaging. Furthermore, a sliding window interlock insures message detection and correctness. In addition, interrupt signals and timer based polling are used as a dual means for detecting communication requests and replies between the controllers.