Electrical computers and digital processing systems: processing – Instruction decoding – Predecoding of instruction component
Reexamination Certificate
2011-03-29
2011-03-29
Treat, William M (Department: 2181)
Electrical computers and digital processing systems: processing
Instruction decoding
Predecoding of instruction component
Reexamination Certificate
active
07917735
ABSTRACT:
A data processing apparatus and method are provided for pre-decoding instructions. The data processing apparatus has pre-decoding circuitry for receiving instructions fetched from memory and for performing a pre-decoding operation to generate corresponding pre-decoded instructions, which are then stored in a cache for access by processing circuitry. For a first set of instructions, each instruction comprises a plurality of instruction portions, and the pre-decoding circuitry generates a corresponding pre-decoded instruction comprising a plurality of pre-decoded instruction portions. If when applying the pre-decoding operation to an instruction in the first set, the pre-decoding circuitry does not have access to all of the plurality of instruction portions of that instruction, the pre-decoding circuitry is arranged to provide in association with at least one pre-decoded instruction portion that it does generate, an indication that the pre-decoded instruction portion relates to an incomplete pre-decoding operation. This provides a simple and effective mechanism for detecting situations where a pre-decoded instruction as later read from the cache may have become corrupted by the pre-decoding operation, and accordingly should not be relied upon.
REFERENCES:
patent: 5335331 (1994-08-01), Murao et al.
patent: 5740461 (1998-04-01), Jaggar
patent: 5761490 (1998-06-01), Hunt
patent: 6009512 (1999-12-01), Christie
patent: 6081884 (2000-06-01), Miller
patent: 6253287 (2001-06-01), Green
patent: 6304963 (2001-10-01), Elwood
patent: 6314509 (2001-11-01), Tremblay et al.
patent: 6560694 (2003-05-01), McGrath et al.
patent: 6807626 (2004-10-01), Cofler et al.
patent: 6820194 (2004-11-01), Bidichandani et al.
patent: 6952754 (2005-10-01), O'Connor et al.
patent: 7415638 (2008-08-01), Smith et al.
patent: 7676659 (2010-03-01), Stempel et al.
patent: 2002/0004897 (2002-01-01), Kao et al.
patent: 2004/0133764 (2004-07-01), O'Connor et al.
patent: 2006/0265573 (2006-11-01), Smith et al.
patent: 2007/0033383 (2007-02-01), Blasco Allue
patent: 2007/0226464 (2007-09-01), Chaudhry et al.
patent: 2007/0260854 (2007-11-01), Smith et al.
patent: WO 2006/125219 (2006-11-01), None
patent: WO 2008/113007 (2008-09-01), None
Widdoes, Jr., “The S-1 Project: Developing High-Performance Digital Computers”, IEEE Computer Society,COMPCON, Feb. 1980, pp. 1-10.
Intrater, “Performance Evaluation of a Decoded Instruction Cache for Variable Instruction Length Computers”,IEEE, vol. 43, No. 10, Oct. 1994, pp. 1140-1150.
Chan et al., “Design of the HP PA 7200 CPU”,Hewlett-Packard Journal, Feb. 1996, pp. 1-11.
AMD-K5 Processor, Publication #18522, Sep. 1996, pp. 1-73.
Klaiber, “The Technology Behind Crusoe Processors”,Transmeta Corporation, Jan. 2000, pp. 1-18.
Smotherman, “S-1 Supercomputer”, May 2006, www.cs.clemson.edu, pp. 1-10.
UK Search Report dated Mar. 23, 2009 for GB 0821520.4.
U.S. Appl. No. 12/010,312, filed Jan. 23, 2008, Greenhalgh et al.
U.S. Appl. No. 12/010,318, filed Jan. 23, 2008, Greenhalgh et al.
U.S. Appl. No. 12/010,305, filed Jan. 23, 2008, Greenhalgh et al.
U.S. Appl. No. 12/010,313, filed Jan. 23, 2008, Greenhalgh et al.
U.S. Appl. No. 12/314,095, filed Dec. 3, 2008, Greenhalgh et al.
Office Action mailed Jun. 8, 2010 in co-pending U.S. Appl. No. 12/010,312.
Office Action mailed Jun. 2, 2010 in co-pending U.S. Appl. No. 12/010,313.
Office Action mailed Nov. 8, 2010 in co-pending U.S. Appl. No. 12/010,312.
ARM Limited
Nixon & Vanderhye P.C.
Treat William M
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