Patent 7263575 was granted and assigned to Denso on August, 2007 by the United States Patent and Trademark Office.
An ECU includes a microcomputer that has an integrated flash memory. An initial writing flag is set in the microcomputer before an initial writing to the flash memory. The microcomputer enters into a writing mode when the flag determines permission of data writing. When the data-writing to the flash memory is completed, the flag is cleared.