Microprocessor with an external command mode for diagnosis and d

Boots – shoes – and leggings

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3642656, 36426791, 364DIG1, 395375, 39518308, 395800, G06F 1134

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active

054796520

ABSTRACT:
A microprocessor is disclosed herein having an external command mode for directly accessing the execution unit, responsive to externally generated commands and instructions. An external instruction path is provided, as well as a conventional processor-driven instruction path. A multiplexer is provided that selects which of the instruction paths is actually supplied to the execution unit. Using the external command mode, the user can examine and modify registers, memory, and I/O space without otherwise affecting their contents. Any instruction executable by the execution unit is executable in the external command mode. Because direct access is provided into the execution unit, there is no implicit updating that would otherwise affect the state of the processor and require saving to an alternate memory. The present invention is implemented with a conventional test access port designed in accordance with the IEEE 1149.1 boundary scan standard, with modification to include an instruction register, a data register, and control logic. The external command mode is applicable to single and multiple pipeline processors. The circuit described herein includes several selectors for selecting between the probe mode and the processor-driven mode of operation, including an external pin, an external command, and a debug exception. For ascertaining if the circuit is in the external command mode, an acknowledge pin is provided to indicate when the execution unit is ready to accept an instruction in the probe model.

REFERENCES:
patent: 3639911 (1972-02-01), Frieband et al.
patent: 3805245 (1974-04-01), Brooks et al.
patent: 3937938 (1976-02-01), Matthews
patent: 4010448 (1977-03-01), Bennett
patent: 4200912 (1980-04-01), Harrington et al.
patent: 4236204 (1980-11-01), Groves
patent: 4312066 (1982-01-01), Bantz et al.
patent: 4403287 (1983-09-01), Blahut et al.
patent: 4404628 (1983-09-01), Angelo
patent: 4422141 (1983-12-01), Shoji
patent: 4455622 (1984-06-01), Loskorn et al.
patent: 4547849 (1985-10-01), Louie et al.
patent: 4644494 (1987-02-01), Muller
patent: 4674089 (1987-06-01), Poret et al.
patent: 4677586 (1987-06-01), Magar et al.
patent: 4720811 (1988-01-01), Yamaguchi et al.
patent: 4734882 (1988-03-01), Romagosa
patent: 4896289 (1990-01-01), Svinicki et al.
patent: 4907150 (1990-03-01), Arroyo et al.
patent: 4914325 (1990-04-01), Yamada
patent: 4945536 (1990-07-01), Hancu
patent: 4949360 (1990-08-01), Martin
patent: 4967326 (1990-10-01), May
patent: 5027273 (1991-06-01), Letwin
patent: 5032983 (1991-07-01), Fu et al.
patent: 5036453 (1991-07-01), Renner et al.
patent: 5036458 (1991-07-01), Matsushima et al.
patent: 5056015 (1991-10-01), Baldwin et al.
patent: 5070476 (1991-12-01), Fujiwara
patent: 5124910 (1992-06-01), Koumoto et al.
patent: 5125088 (1992-06-01), Culley
patent: 5128970 (1992-07-01), Murphy
patent: 5136714 (1992-08-01), Braudaway et al.
patent: 5175853 (1992-12-01), Kardach et al.
patent: 5218525 (1993-06-01), Amaski et al.
patent: 5222068 (1993-07-01), Burchard
patent: 5228039 (1993-07-01), Knoke et al.
patent: 5254942 (1993-10-01), D'Souza et al.
patent: 5263143 (1993-11-01), Robinson et al.
patent: 5265005 (1993-11-01), Schmidt et al.
patent: 5274826 (1993-12-01), Kardach et al.
patent: 5274834 (1993-12-01), Kardach et al.
patent: 5276824 (1994-01-01), Skruhak et al.
patent: 5276888 (1994-01-01), Kardach et al.
patent: 5281864 (1994-01-01), Hahn et al.
patent: 5291604 (1994-03-01), Kardach et al.
patent: 5329471 (1994-07-01), Swoboda et al.
patent: 5339437 (1994-08-01), Yuen
patent: 5353424 (1994-10-01), Partovi et al.
Albitz, Gary, "Superstate: Beyond Hardware Solutions", Microprocessor Report, pp. 6-5 to 6-6.
Ching, Carl, "Solutions to NS16000 Family Microprocessor Emulation Design Challenges", IEEE, 1983, pp. 1-14.
Christensen, Fred, "Advanced System/Software Development Tools Using System V/68, A Unix-Derived O.S. for the M68000 Family", IEEE, pp. 1-9.
Ellis, Simon C., "The Intel System Management Mode", Microprocessor Report, pp. 6-1 to 6-2.
Gephardt, Doug, et al., "System Management Mode in Am386 Microprocessors", Microprocessor Report, pp. 6-3 to 6-4.
Hamilton, Gail, "Evaluating Software Performance in Microprocessor Design", IEEE, 1983, pp. 1-5.
Handy, Jim, "Software Tools to Match Growing Microprocessor Sophistication", IEEE, 1983, pp. 1-5.
Marshall, John, "A Comprehensive Processor Support Strategy", IEEE, pp. 1-3.
Swope, William A., "Developing a Product in a Software Intensive Design", IEEE, pp. 1-7.
Thorson, Mark, "System Management Mode Explained", Microprocessor Report, pp. 6-7 to 6-10.
Vandenheede, Dr. T. M., "Advanced In-Circuit Emulation Design", IEEE, pp. 1-4.
Search Report dated Oct. 7, 1994.
Bursky, Dave, "Dedicated Emulation Logic on Chip Debugs Digital Processor's Hardware and Software", Electronic Design, May 10, 1990, pp. 29-30.
Williams, Tom, "On-Chip Test Logic Aids Emulation of Complex Processors", Computer Design, vol. 29, No. 19, Oct. 1, 1990, pp. 68-72.

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