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:
Apr. 07, 1987
Filed:
Feb. 14, 1984
Nobuhiko Ohno, Tokorozawa, JP;
Katsumi Ogiue, Tokyo, JP;
Katsuya Mizue, Koganei, JP;
Noriyoshi Okuda, Mitaka, JP;
Hitachi, Ltd., , US;
Abstract
A read-only memory has a terminal for receiving a writing current and a data input/output terminal. In the writing operation, the writing current is supplied to the terminal which is different from the data input/output terminal. Therefore, a data output circuit can be constituted by an ECL circuit having a relatively low withstand voltage, and a selection circuit related to the reading operation is achieved by using an ECL circuit. Accordingly, the read-only memory performs the reading operation at high speeds. During the writing operation, a different selection circuit is used which can withstand high voltages.