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:
Jan. 20, 1976
Filed:
Sep. 24, 1973
Roger J Fisher, Houston, TX (US);
Gerald D Rogers, Houston, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A read-only-memory for use in an electronic calculator or the like, implemented in a large-scale-integrated MOS semiconductor chip. The ROM is designed to save area on the chip by employing a virtual ground feature and conserve power by a precharge system. The memory cells are in an array defining X and Y lines, with the presence or absence of a bit being determined by thin oxide under an X line between adjacent Y lines. Ground lines are provided for groups of Y lines, and the Y-decode matrix includes an arrangement for connecting a selected Y-line to a non-adjacent ground line. Only the X decode section is precharged rather than all the X lines. The entire decode and read out is accomplished in a small part of the instruction cycle of the calculator.