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:
Jun. 21, 2005
Filed:
Jul. 23, 2003
Hiroyuki Sadakata, Osaka, JP;
Naoki Kuroda, Kyoto, JP;
Hiroyuki Sadakata, Osaka, JP;
Naoki Kuroda, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In recent system LSIs, a plurality of RAMs differing in capacity and in bit width have come to be mounted on a single chip according to the needs on the system side. However, when testing the plurality of RAMs, if the RAMs differ in capacity, they cannot be tested using the same test pattern (for example, HALF-MARCH) even if a special pin is provided for each RAM, because X, Y address mapping differs between the different RAMs; accordingly, the test has to be performed by dividing the RAMs into groups each consisting of RAMs having the same memory space, and this has lead to increased test time. An external address signal and a test-only address signal are provided as RAM control signals and, in the latter case, the number of X, Y addresses in each of the RAMsandis set equal to that of the largest capacity RAMwithin the same chip, thereby making the X, Y address mapping the same for all the RAMsto