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. 26, 1994
Filed:
Nov. 27, 1989
Toshiyuki Kataoka, Tokyo, JP;
Kazutoshi Yoshizawa, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A microcomputer includes a central processing unit (CPU) and an electrically erasable and programmable nonvolatile memory (EEPROM) fabricated on a single semiconductor chip. When CPU issues a data write request to EEPROM, a data write control circuit is initiated to perform a data write-processing in which data in an address of EEPROM selected by CPU is first erased and thereafter data from CPU is written into that selected address. There is further provided an over-written detection circuit for detecting that CPU issues another data write request to EEPROM while the data write control circuit is performing the data write-processing and for producing an over-write detection signal to CPU.