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. 16, 2002
Filed:
Jun. 09, 2000
Nobuhiro Tomari, Miyazaki, JP;
Oki Electric Industry Co, Ltd., Tokyo, JP;
Abstract
A charge pump circuit boosts a power supply voltage to generate a high voltage VPP in response to clocks CK, CK/ supplied from an oscillation circuit . A voltage detecting circuit discriminates whether the high voltage VPP reaches a desired voltage value or not and represents it by discrimination signals LVPP, DIS/. If the high voltage VPP does not reach the desired voltage value, a writing control circuit stops the oscillation circuit from effecting its oscillating operation and stops the charge pump circuit from boosting the power supply voltage to the high voltage VPP in response to the discrimination signal DIS/. Accordingly, the high voltage VPP having a desired voltage value is not applied to a memory cell of a memory circuit so that writing is not effected. Further, the discrimination signal LVPP, is outputted externally so as to represent the writing state in the memory cell.