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. 12, 2002
Filed:
Dec. 10, 1999
Tomohiro Nakayama, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
Memory cell blocks to are respectively provided with mask ROM cell rows and different values from one another are respectively stored in the mask ROM cell rows. A mask ROM cell row selecting circuit makes transfer gates of mask ROM cells in a memory cell block corresponding to a block selection signal BSi turned on when a test mode signal *TM and the block selection signal BSi are both active wherein i=1 to 7. A word line selection signal is made inactive when the test mode signal *TM is active. Tests on short between address signal lines and other defects are effected in a procedure wherein a test mode is activated, block selection signals are sequentially activated to read contents of mask ROM cell rows and the contents are compared with expected values.