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:
Oct. 30, 1990
Filed:
Aug. 09, 1989
Saad A Jamoua, Oak Park, MI (US);
Stephen W Hoffman, Riverview, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A dual port, random access, read/write memory is provided such that each microprocessor can access shared memory locations without regard to the state of the other microprocessor. Previously known dual port systems use delays, called wait states, or handshaking techniques to control memory acces and to resolve overlapping memory access requests. This invention avoids the need for special timing controls by improving memory response time. Once a valid address is placed on the address bus by the microprocessor, which is recognized by the memory as being within its range of assigned address values, the memory prefetches the data at that address may soon follow. If it does, then the data is placed on the data bus. If it does not, then the prefeteched data is ignored and a write operation takes place for the particular address.