System for altering operation of a graphics subsystem during run-time to conserve power upon detecting a low power condition or lower battery charge exists

• US 6,691,236 B1
• Filed: 10/28/1999
• Issued: 02/10/2004
• Est. Priority Date: 06/03/1996
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Atkinson, Lee
• Primary Examiner(s): Butler, Dennis M.
• Assistant Examiner(s): SURYAWANSHI, SURESH
• Application Number:
  US09/429,554
• Time in Patent Office: 1,566 Days
• Field of Search: 713/320, 713/322, 713/501, 713/323, 713/340, 713/300, 713/500
• US Class Current: 713/320
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3218 of display devices
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A system and process for power conservation in a portable computer system. When the application or hardware in use allows for reduced video performance, the refresh rate of the video graphics controller is reduced to a level which allows practical use of the display but consumes much less power than a normal mode.

Claims

1. A computer system with reduced power consumption, comprising:

a central processing unit; and

a video graphics controller engine connected to said central processing unit;

memory which is operatively connected to said video graphics controller engine;

wherein said video graphics controller engine is configured to shift between operable high-performance and operable low-power modes, dynamically and reversibly, in dependence on power conservation inputs;

wherein said power conservation inputs can include at least one of;

critically low output from system power supply, or when the system is being stored to a non-volatile memory; and

wherein said high-performance and low-power modes of said video graphics controller engine differ in at least one of;

memory interface clock rate, core logic supply voltage, and core logic rate.

2. A computer system with reduced power consumption, comprising:

a central processing unit;

a video graphics controller engine coupled to said central processing unit; and

memory which is operatively connected to said video graphics controller engine;

wherein said video graphics controller engine includes a memory interface clock which is used to refresh said memory and a video clock which is used to refresh a display;

wherein said memory interface clock is dynamically adjusted during run-time, said adjustment to the memory interface clock is made upon determining that the performance of the video graphics controller can be changed; and

further including a battery that provides power for said computer system and wherein said memory interface clock is slowed down, but remains operating, upon determining that a low battery condition has occurred.

3. The computer system of claim 2 wherein said memory interface clock is slowed down upon determining that the performance of the video graphics controller can be reduced.

4. The computer system of claim 2 wherein said memory interface dock is sped up upon determining that the performance of the video graphics controller should be increased.

5. The computer system of claim 2 wherein said memory interface clock is dynamically adjusted upon determining that the activity of the central processing unit has changed causing a change in the needed performance of the video graphics controller.

6. The computer system of claim 5 wherein said memory interface clock is sped up upon determining that the activity of the central processing unit has increased.

7. The computer system of claim 5 wherein said memory interface clock is slowed down upon determining that the activity of the central processing unit has decreased.

8. The computer system of claim 2 further including video bus mastering hardware and wherein said memory interface clock is dynamically adjusted upon determining that the activity of the video bus mastering hardware has changed.

9. The computer system of claim 8 wherein said memory interface dock is sped up upon determining that the activity of the video bus mastering hardware has decreased.

10. The computer system of claim 8 wherein said memory interface clock is slowed down upon determining that the activity of the video bus mastering hardware has increased.

11. The computer system of claim 2 wherein said video clock also is dynamically adjusted upon determining that the performance of the video graphics controller can be changed.

12. A computer system with reduced power consumption, comprising:

a central processing unit;

a battery used to power said computer system;

a video graphics controller engine coupled to said central processing unit;

a display coupled to said video graphics controller engine; and

memory which is coupled to said video graphics controller engine;

wherein said video graphics controller engine includes a memory interface clock which is used to refresh said memory; and

wherein said memory interface clock is dynamically adjusted during run-time while the display continues to be used, said adjustment to the memory interface clock is made upon detecting a low power condition.

13. A computer system with reduced power consumption, comprising:

a central processing unit;

a battery;

a video graphics controller engine coupled to said central processing unit; and

memory which is operatively connected to said video graphics controller engine;

wherein said video graphics controller engine can be configured to operate in either of at least two selectable operational modes including a high performance mode and a low performance mode wherein a display is usable in either mode to show images; and

wherein a performance mode is dynamically selected for the video graphics controller based on a determination during run-time of whether the battery is in a low battery condition.

14. The computer system of claim 13 wherein a difference between the high and low performance modes includes a difference in the speed of the video graphics controller.

15. The computer system of claim 13 wherein the video graphics controller includes a memory interface clock used to refresh said memory and wherein a difference between the high and low performance modes includes a difference in the speed of the memory interface clock.

16. A computer system, comprising:

a central processing unit;

a graphics subsystem coupled to said central processing unit; and

a battery used to power said computer system;

wherein the operation of the graphics subsystem is altered during run-time so as to conserve power upon detecting a low power condition or lower battery charge exists.

17. A computer system, comprising:

a battery used to power said computer system;

a video graphics engine; and

memory coupled to said video graphics engine;

wherein said video graphics engine includes a memory interface dock which is used to refresh said memory; and

wherein said memory interface dock is dynamically adjusted during run-time so that graphics data can be provided to a display, said adjustment to the memory interface dock is made upon detecting a low power condition.