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:
Sep. 21, 1993
Filed:
Sep. 11, 1990
Akihiro Yoshitake, Kawasaki, JP;
Toshiharu Ohashima, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A data processor decoding and executing a train of instructions including a plurality of sets of an instruction code field and a corresponding addressing field. The data processor includes a decoding unit for decoding the instruction code field and the corresponding addressing field, and outputting an instruction tag information and an addressing information, respectively, in response to a control signal generated at a predetermined frequency; a holding unit for holding the addressing information fed from the decoding unit, and outputting a holding result in response to the control signal; and a detecting unit responsive to the instruction tag information, addressing information and holding result. The detecting unit effects a judgement of whether the instruction tag information indicates that it is an instruction to check undefined addressing of the addressing field decoded in the preceding stage or in the present stage, and detects the undefined addressing based on a result of the judgement. As a result, it becomes possible to check undefined addressing prescribed for each instruction without lowering instruction execution performance of the data processor.