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:
Feb. 27, 1990
Filed:
Aug. 29, 1988
Richard A Pidsosny, Canton, MI (US);
Michael J Burke, Milford, MI (US);
Mark W Jarvis, Unionville, CA;
Ford Motor Company, Dearborn, MI (US);
Abstract
An apparatus for replacing an undesired code stored in a plurality of storage locations in read-only memory (ROM) with a replacement code. The replacement code, including a jump-back instruction to readdress the ROM, are programmed into an EEPROM. First and second storage locations store the beginning address of the undesired code and the beginning address of the replacement code, respectively. When the beginning address of the undesired code is generated by a program counter, a comparator generates a transfer signal. In response, the beginning address of the replacement code stored in the second storage location is transferred into the program counter. Each address of the replacement code is then sequenced by the program counter until a central processing unit recognizes the jump-back instruction. The central processing unit then readdresses the ROM in response to the jump-back instruction after the entire replacement code has been executed in place of the undesired code.