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:
Jul. 16, 1985
Filed:
Aug. 17, 1982
Yasushi Fukunaga, Hitachi, JP;
Tadaaki Bandoh, Tohkai, JP;
Kotaro Hirasawa, Hitachi, JP;
Hidekazu Matsumoto, Hitachi, JP;
Jushi Ide, Mito, JP;
Takeshi Katoh, Hitachi, JP;
Hiroaki Nakanishi, Hitachi, JP;
Tetsuya Kawakami, Hitachi, JP;
Ryosei Hiraoka, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Engineering Co., Ltd., Tokyo, JP;
Abstract
A central processing unit for executing instructions of variable length in which an operand specifier for specifying the addressing mode of an operand is independent of an operation code for ascertaining the kind of an operation and the number of operands. Each operand specifier is formed of one or more data bytes, and has a stop bit flag indicating whether or not the particular operand specifier is the last operand specifier. By adding the stop bit flag, the operand specifier can be shared, and different processing can be executed with an identical operation code. In a case where, when operation code decoding means has provided an output indicative of the last operand, the stop bit flat is not detected in the corresponding operand specifier, the corresponding instruction is detected as an error.