Suspend/resume capability for a protected mode microprocessor

US6223293A · kind A · utility

Assignee

• NEC CORPORATION · JP

Inventors

• Mark J. Foster · Acton, US
• Saifuddin Fakhruddin · Three Rivers, US
• James Les Walker · Cedar Park, US
• Matthew B. Mendelow · Austin, US
• Jiming Sun · Issaquah, US
• Rodman S. Brahman · Benton Harbor, US
• Michael P. Krau · Benton Harbor, US
• Brian D. Willoughby · Midland, US
• Michael D. Maddix · Midland, US
• Steven L. Belt · Three Rivers, US
• Scott A. Hovey · Three Rivers, US
• Mark A. Ruthenbeck · Gurnee, US

Key dates

• Filing date: Feb 16, 1995
• Grant date: Apr 24, 2001
• Expiry date: Feb 16, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02D10/00
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A laptop computer system includes a protected mode microprocessor capable of operating in restricted and unrestricted modes, and an arrangement which in response to a predetermined condition saves information from the processor and then forcibly switches the processor to its unrestricted mode of operation. When running a multi-tasking operating system where an application program is being executed in a restricted mode, a suspend/resume operation can be carried out in which the system is substantially powered down and then powered back up, and will resume the interrupted application with the restricted mode back in effect. Further, setup changes such as adjustment of the processor speed can be made without exiting the application program running in the restricted mode.