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. 24, 2000
Filed:
Feb. 25, 1999
Denso Corporation, Kariya, JP;
Abstract
A vehicle electronic control unit (ECU) prevents its power supply from being cut off while it is in the process of re-programming data in a re-programmable nonvolatile memory. An ECU includes a microcomputer which, after receiving a re-program request from a re-programming device, determines if an identification code in a flash memory and an identification code from the re-programming device match. If the codes do match, the microcomputer executes re-program processing for overwriting all the data in the flash memory, including a control program. The ECU is supplied with power from a battery by way of a main relay whose contacts are closed when a vehicle ignition switch (IGSW) is turned on or when a drive signal is applied to the relay. When the IGSW starts to operate, the microcomputer outputs the drive signal to the main relay and, when it completes re-program processing and the IGSW is off, the microcomputer stops outputting the drive signal. Thus even if the IGSW is switched off during execution of re-program processing, power to the microcomputer is maintained so that the re-program processing is not interrupted.