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. 26, 1991
Filed:
Oct. 05, 1989
James H Scheuneman, St. Paul, MN (US);
Lawrence R Fontaine, Minneapolis, MN (US);
Unisys Corp., Detroit, MI (US);
Abstract
Accessing control means and methods are provided for controlling the granting of access by a plurality of requestors to a commonly shared unit on a predetermined priority basis. An addressable programmed memory, such as a ROM, is programmed to provide a predetermined access priority. The ROM operates in response to sequentially applied addresses to produce ROM outputs which determine the manner in which access is granted to the requestors. Each ROM output also includes history outputs which are fed back and combined with requestor signals to form each ROM address, whereby requestor access grating selection is determined based on previous access granting history as well as on current request status.