Electrical computers and digital processing systems: processing – Processing control – Mode switch or change
Reexamination Certificate
2005-05-24
2005-05-24
Pan, Daniel W. (Department: 2183)
Electrical computers and digital processing systems: processing
Processing control
Mode switch or change
C712S219000, C712S225000, C711S201000, C711S208000, C711S209000, C710S033000
Reexamination Certificate
active
06898697
ABSTRACT:
A processor is configured to operate in a modes which utilize segmentation and which do not utilize segmentation. The processor includes circuitry which is configured to detect and respond to mode and state changes. The circuitry is configured to determine whether a segmentation state of the processor changes in response to execution of a control transfer operation. If the segmentation state does not change as a result of the transfer instruction, execution of instructions may continue sequentially and a corresponding first check performed. However, if the segmentation state does change as a result of the transfer instruction, a flush of the pipeline is initiated prior to performing a corresponding second check. When a first mode of operation is detected a limit check may be performed, while a canonical check may performed when a second mode of operation is detected. A special register is defined which is configured to indicate changes in segmentation state subsequent to a control transfer operations. A read of the special register may then be performed in order to determine whether a state change is indicated.
REFERENCES:
patent: 5129070 (1992-07-01), Dorotte
patent: 5255379 (1993-10-01), Melo
patent: 5297282 (1994-03-01), Meilak et al.
patent: 5303378 (1994-04-01), Cohen
patent: 5729675 (1998-03-01), Miller et al.
patent: 5784713 (1998-07-01), McMahan
patent: 6101600 (2000-08-01), Arnold et al.
patent: 6807616 (2004-10-01), McGrath et al.
U.S. Appl. No. 09/483,101, filed Jan. 2000, McGrath et al.*
U.S. Appl. No. 09/808,702, filed Mar. 2001, Ahmed et al.*
The Technology Behind Crusoe™ Processors, Low-Power x86-Compatible Processors Implemented with Code Morphing™ Software, Transmeta Corporation, Jan. 2000, pp. 1-18.
Alpha Learns to Do Windows; Digital's FX!32 is The Key to Running Win32 Software on Alpha/Windows NT.,Selinda Chiquoine, BYTE, Aug. 4, 1998, 4 pages.
Awards Stack Up for DIGITAL FX!32 Windows Compatibility Software for ALPHA,DIGITAL Press Release, Dec. 11, 1 997, 7 pages.
DIGITAL FX!32; White Paper: How DIGITAL FX!32, Works,DIGITAL Semiconductor, Jan. 26, 1998, 4 pages.
An Alpha in PC Clothing; Digital Equipment's New x86 Emulator Technology Makes An Alpha System a Fast x86 Clone,Tom Thompson, BYTE, Aug. 4, 1998, 7 pages.
AMD 64-Bit Technology; The AMD x86 Architecture Programmers Overview,AMD, Publication #24108 Rev: A, Aug 2000, pp. 1-106.
AMD 64-Bit Technology; The AMD x86-64 Architecture Programmers Overview,AMD, Publication #24108 Rev: C, Jan. 2001, pp. 1-128.
Intel Architecture Software Developer's Manual, vol. 1: Basic Architecture,© Intel Corporation 1996, 1997, pp. 3-1 through 3-15.
Pentium® Pro Family Developer's Manual,vol. 3:Operating System Writer's Guide,© Intel Corporation 1996, Chapters 2-4, pp. 2-1 through 4-29.
Alpha 21264 Microprocessor Hardware Reference Manual,Compaq Computer Corporation, 1999, pp. 5-4 to 5-6.
PowerPc Microprocessor Family: The Programming Environments,Motorola, Inc., 1997, Chapter 4 pages 4-1 to 4-9, Chapter 7 pages 7-1 to 7-124.
Clark Michael T.
Gao Hongwen
Keltcher Chetana N.
Advanced Micro Devices , Inc.
Meyertons Hood Kivlin Kowert & Goetzel P.C.
Pan Daniel W.
Rankin Rory D.
LandOfFree
Efficient method for mode change detection and synchronization does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Efficient method for mode change detection and synchronization, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient method for mode change detection and synchronization will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3420061