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:
Mar. 09, 1982
Filed:
Apr. 21, 1980
Toshitaka Fukushima, Yokohama, JP;
Kazumi Koyama, Kanagawa, JP;
Kouji Ueno, Kawasaki, JP;
Tamio Miyamura, Kawasaki, JP;
Yuichi Kawabata, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A program circuit for permanently storing data into a programmable read only memory. A programming current (received from an external source) is connected to the selected bit line through a Darlington pair which is controlled by the bit decoding circuitry. Thus, the bit decoding circuitry is not required to pass the large programming current, and the programming current is not significantly shunted away from the selected bit line. To facilitate use of the Darlington configuration, a constant current source is provided for each bit line within a set of bit lines. The program circuit includes at least one switching means for connecting the program current to a selected bit line, a bit decoder connected to the control inputs of the switching means for selecting a bit line in response to the addressing signals input to the bit decoder and a control current supplying means for supplying a control current to the control inputs of the switching means.