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:
Mar. 21, 2000
Filed:
Jan. 05, 1998
William J Cannon, Centerville, OH (US);
David K Remnant, Dayton, OH (US);
Paul D Ward, Franklin, OH (US);
Timothy R Hoerig, Beavercreek, OH (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
A method and apparatus for emulating instructions of one microprocessor ('legacy instructions') with instructions of another microprocessor with an incompatible instruction set which provides increased throughput relative to known emulation systems. In particular, the legacy instructions are translated into direct vectors to software routines for each legacy instruction. Rather than fetching the legacy instruction and interpreting the instruction in software, the emulation system and method in accordance with the present invention fetches the direct vectors to the software routines which emulate the legacy instructions. The legacy instructions can either be translated by way of software when the legacy memory is loaded or modified, or by way of hardware when legacy memory is accessed. By fetching the direct vectors, the need for software-based look-up tables for interpreting the legacy instructions is obviated. As such, the probability of cache misses is greatly reduced which increases the throughput of the system.