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:
Aug. 31, 1993
Filed:
Jun. 27, 1990
Tetsuya Nakagawa, Millbrae, CA (US);
Masafumi Miyamoto, Koganei, JP;
Yasuhiro Sagesaka, Kodaira, JP;
Toru Baji, Burlingame, CA (US);
Hitachi Ltd., Tokyo, JP;
Abstract
A data processor comprises a plurality of registers 1 (registers a to d), a plurality of data saving stack memory devices 2 coupled to the registers 1 for exclusive use thereof, respectively, and an instruction decoder for decoding instructions for controlling the registers 1 and the data saving stack memory devices 2 in accordance with the result of the instruction decoding. In response to an instruction 'PUSH', the contents of the registers 1 (registers a to d) are selectively saved to the data saving stack memory device 2. In response to a instruction 'POP', the contents of the data saving stack memory devices 2 are selectively restored to the registers 1 (registers a to d). Each of the instructions 'PUSH' and 'POP' has a field for indicating need or needlessness of the saving and restoration for each of the registers 1 and each of the data saving memories 2.