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:
Apr. 18, 2000
Filed:
Dec. 17, 1997
Teruyuki Maruyama, Yokosuka, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A memory unit and method for using the memory unit in a tightly coupled multiprocessor system having a split model bus is configured to perform an atomic transaction that is carried out in a synchronous mode on the basis of semaphore variables or lock variables. A decoder is included in the memory unit and generates an atomic address space and a conventional address space in an address space of a RAM portion of the memory unit. An identifier unit identifies whether a memory access request is from a bus master and is for an atomic address space or for the conventional and address space. Based on whether the access request is for the atomic address space or the conventional address space controls an atomic transaction mode-shifting unit to shift between an atomic transaction mode of operation and a normal mode of operation.