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:
Feb. 04, 2003
Filed:
Jul. 21, 2000
Tadato Yamagata, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A memory module is provided with switch groups (SD to SD ) in corresponding relation to data lines (DQ to DQ ) connected to memory devices (MD to MD ). The switch groups (SD to SD ) connect all of the data lines (DQ to DQ ) to a portion external to the memory module (MMa) in a memory operation, and connect all of the data lines (DQ to DQ ) to inputs of an exclusive NOR circuit (EXa) after common 1-bit data is written into the memory devices (MD to MD ) in a testing operation. A malfunction of the memory devices (MD to MD ) is detected using an output signal (TMSa) from the exclusive NOR circuit (EXa). The memory module is accomplished which allows an inexpensive tester to conduct an electrical assembly check and a simple data write and read operation test upon the memory devices, which includes a small number of I/O pins for the check and test, and which does not deteriorate data input/output characteristics of the memory devices.