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:
Jun. 20, 1995
Filed:
Feb. 25, 1994
Yasuhiro Okuda, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A read only memory capable of writing data, which is provided with a number of '0' judging circuit (8) judging whether or not the number of bits of '0' of data to be written in the memory cell array (1) is more than a half or more of a predetermined bit length, a monitor bit cell group (9) storing the above judge result by corresponding it to the respective data, and with a data inverting select circuit (12) outputting the values of the respective bits of the data after inverting them to a data writing/reading circuit (2) when the number of bits of '0' in the data to be written is judged to be a half or more of the predetermined bit length, and outputting the values of the respective bits of data read from the memory cell array (1) after inverting them when the monitor bit cell group (9) stored that the number of bits of '0' in the data to be read is a half or more of the predetermined bit length, and is capable of reducing an aluminum width of a power source of a PROM, and, when the data length to be written by one writing operation is enlarged, is no need to enlarge the aluminum width of the power source line and is capable of reducing electric current to be consumed for there.