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:
Jan. 07, 1997
Filed:
Jul. 02, 1993
Toru Okatani, Kobe, JP;
Yoichi Kawabuchi, Toyokawa, JP;
Syuzi Maruta, Toyokawa, JP;
Keiichi Nomura, Amagasaki, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
A program replacement device is incorporated in a computer system having a CPU and a program memory in which first programs to be executed by the CPU are stored. The program replacement device includes a RAM employed as the program memory and having a write enable terminal, and a protection circuit interposed between the write enable terminal of the program memory and a write signal outputted from the CPU. The protection circuit includes a push switch for instructing program replacement with respect to the program memory, a pulse generating circuit for generating a pulse signal having a given time interval in response to an instruction from the push switch, and a gate circuit for making, only when the pulse signal is generated, the write signal outputted from the CPU valid with respect to the write enable terminal of the program memory. The program replacement device further includes an interruption generating circuit for generating in the CPU an interruption required to write second programs in the program memory in response to the instruction from the instruction section, thereby replacing the first programs by the second programs.