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:
Oct. 19, 1999
Filed:
Oct. 31, 1997
Applicant:
Inventors:
Hideki Sunaga, Tokyo, JP;
Masatoshi Suto, Tokyo, JP;
Assignee:
Calsonic Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
713-1 ; 713202 ;
Abstract
An external interrupt port is installed for writing a password into a random access memory by monitoring low voltage with an interrupt when a battery is turned off and on instantaneously and performing ignition off processing. During Random access memory initialization the system disables an external interrupt and initializes output of ports containing the external interrupt port when an ignition switch is turned on, next makes a password check just after initializing output of the ports, then enables an external interrupt and executes initialization.