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. 17, 1995
Filed:
Jun. 05, 1992
Hiroyasu Makihara, Hyogo, JP;
Kenji Kohda, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A mask ROM having an ECC for error correction by carrying out operation according to a Hamming matrix in which all but 2 of 6 elements in one column and the other column match each other. The columns correspond to 32 data that will be provided to an external source, and the one column corresponds to the other column by 16 columns. The ECC is implemented so that one half of 32 correction signals with which exclusive ORs are to be taken with 32 data, are generated by a circuit identical to that of a circuit for generating the other half of the 32 correction signals; and the circuit for taking the exclusive ORs from one half of the 32 data and the corresponding correction signals can be used for taking exclusive ORs from the remaining half of the 32 data and the corresponding correction signals. The number of component elements for the correction signal generator and for the data correction circuit, and the number of input signal lines to the data correction circuit are reduced to a half, alleviating the circuit complexity of the entire ECC in comparison with that of a conventional one.