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. 26, 1998
Filed:
Feb. 10, 1995
James Allan Kahle, Austin, TX (US);
Albert J Loper, Cedar Park, TX (US);
Soummya Mallick, Austin, TX (US);
Aubrey Deene Ogden, Round Rock, TX (US);
John Victor Sell, Los Altos, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and system for permitting the selective support of non-architected instructions within a superscalar processor system. A special access bit within the system machine state register is provided and set in response to each initiation of an application during which execution of non-architected instructions is desired. Thereafter, each time a non-architected instruction is decoded the status of the special access bit is determined. The non-architected instruction is executed in response to a set state of the special access bit. The illegal instruction program interrupt is issued in response to an attempted execution of a non-architected instruction if the special access bit is not set. In this manner, for example, complex instruction set computing (CISC) instructions may be selectively enabled for execution within a reduced instruction set computing (RISC) data processing system while maintaining full architectural compliance with the reduced instruction set computing (RISC) instructions.