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:
Mar. 19, 1991
Filed:
Jun. 27, 1989
James T Koo, Los Altos Hills, US;
In-Nan Wu, Sunnyvale, US;
Francis C Hung, Cupertino, US;
King Wang, Milpitas, US;
Jon C Zierk, Cupertino, CA (US);
Vitelic Corporation, San Jose, CA (US);
Abstract
The present invention is a controller for producing a dual port function from a single port memory with an improved memory cycle time. An address or control signal transition for one port generates an access request signal for that port. The access request signal both (1) blocks an access request by the other port for its duration and (2) generates a series of signals for a memory access for the selected port. A multiplexer for providing addresses to the memory core from two ports is switched to select a second port while a first port access is in progress. The output of the multiplexer is not enabled until the memory core access is completed. Thus, the set-up time for the second set of addresses is allowed to overlap the memory core access time for the first set of addresses thereby reducing overall cycle time.