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:
May. 28, 1991
Filed:
Nov. 28, 1988
Atsuo Yamaguchi, Itami, JP;
Kenichi Takahira, Itami, JP;
Shigeru Furuta, Itami, JP;
Takesi Inoue, Itami, JP;
Toshiyuki Matsubara, Itami, JP;
Shuzo Fujioka, Itami, JP;
Abstract
An IC card includes an addressable CPU having a memory space including a special area including a first plurality of memory addresses which are addressable with a short instruction word, first and second memories in which test and application programs are stored, respectively, a bus which connects the CPU and the first and second memories, a first selection circuit for forming a first memory mapping arrangement in which at least a portion of the first memory is superimposed on the special area, a second selection circuit for forming a second memory mapping arrangement in which at least a portion of the second memory is superimposed on the special area, a detection circuit for detecting the execution of the test program or the application program, and a changeover circuit arranged to selectively operate the first and second selection circuits according to the result of detection executed by the detection circuit. The above-described arrangement makes it possible to effectively use the special area to efficiently execute either the application program or the test program.