System and method of controlling a graphics controller

• US 20060119603A1
• Filed: 12/03/2004
• Published: 06/08/2006
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Neysadurai, Anura, Chen, Qijun, Lakdawala, Rahul V.
• Granted Patent: US 7,502,947 B2
• Time in Patent Office: Days
• US Class Current: 345/502
• CPC Class Codes: G06F 3/1438 using more than one graphics controller
• CPC Class Codes: G09G 2330/02 Details of power systems and of start or stop of display operation
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04

Abstract

A system comprises a first graphics controller adapted to couple to a first display, a second graphics controller adapted to couple to a second display, and a switch through which at least one of communications and power is provided to the second graphics controller. The system also comprises control logic coupled to the switch. The control logic causes the switch to preclude at least one of communications and power from being provided to the second graphics controller if the second display is not operatively coupled to the system.

Claims

1. A system, comprising:

a first graphics controller adapted to couple to a first display;

a second graphics controller adapted to couple to a second display;

a switch through which at least one of communications and power is provided to said second graphics controller; and

control logic coupled to the switch, said control logic causes said switch to preclude at least one of communications and power from being provided to said second graphics controller if the second display is not operatively coupled to said system.

2. The system of claim 1 wherein said control logic is adapted to receive a detect signal that indicates whether the second display is operatively coupled to said system.

3. The system of claim 1 wherein said control logic asserts an enable signal to said switch based on said detect signal.

4. The system of claim 1 wherein the control logic causes said switch to disable power to said second graphics controller.

5. The system of claim 1 wherein said system comprises a connector adapted to be coupled to the second display and, upon coupling the second display to said connector, said control logic causes said switch to enable at least one of communications and power to be provided to said second graphics controller.

6. The system of claim 1 wherein if the second display is operatively coupled to said system during run-time, said control logic dynamically causes said switch to enable at least one of communications and power to be provided to said second graphics controller and, if the second display is operatively removed said system during run-time, said control logic dynamically causes said switch to preclude at least one of communications and power from being provided to said second graphics controller.

7. The system of claim 1 wherein said dynamically-controllable switch is used to provide power to said second graphics controller and said system further comprises another switch coupled to the control logic for providing communications to the second graphics controller.

8. The system of claim 1 wherein said switch is dynamically-controllable during run-time of said system.

9. A system, comprising:

a first graphics controller adapted to couple to a first display;

a second graphics controller adapted to couple to a second display via a connector;

a power switch that provides power to said second graphics controller; and

control logic coupled to the connector and to the power switch, said control logic causes said power switch to disable power to said second graphics controller if the second display is not coupled to said connector.

10. The system of claim 9 wherein said switch allows power to be provided to said second graphics controller separately from power to said first graphics controller.

11. The system of claim 9 further comprising a graphics switch coupled to said first and second graphics controllers, and wherein said control logic causes said graphics switch to disable said data signals from being provided to said second graphics controller if the second display is not coupled to said connector.

12. The system of claim 11 wherein, through said graphics switch, data signals pass from the first graphics controller to said second graphics controller

13. The system of claim 9 wherein the control logic causes said power switch to disable power to said second graphics controller while said first graphics controller continues to be powered on.

14. The system of claim 9 wherein, upon coupling the second display to said connector, said control logic causes said power switch to enable power to said second graphics controller.

15. A system, comprising:

a first graphics controller adapted to couple to a first display;

a second graphics controller adapted to couple to a second display; and

control logic coupled to the second graphics controller and said control logic causes said second graphics controller to be in one of a plurality of power states based on whether the second display is operatively coupled to the system.

16. The system of claim 15 wherein said first graphics controller provides data to said second graphics controller to be displayed on the second display.

17. The system of claim 15 wherein said second graphics controller can be in a different power state than the first graphics controller.

18. The system of claim 15 wherein, upon determination that the second display is not operatively coupled to the system, said control logic causes said second graphics controller to transition to a lower power state.

19. The system of claim 18 wherein, upon a subsequent determination that the second display is operatively coupled to said system, said control logic causes said second graphics controller to transition out of the lower power state.

20. The system of claim 15 wherein the control logic receives a display detect signal from said connector, said display detect signal indicates whether the second display is operatively coupled to the system, and, on the basis of the display detect signal, said control logic asserts a control signal to said second graphics controller to cause said second graphics controller to be in a particular power state from among the plurality of power states.

21. The system of claim 15 wherein said control logic causes said second graphics controller to be in one of a plurality of power states by asserting a signal to the first graphics controller which, in turn, transmits a command to the second graphics controller, said command dictating the particular power state for the second graphics controller.

22. The system of claim 15 further comprising a keyboard controller adapted to receive input signals from a keyboard, wherein said control logic causes said second graphics controller to be in one of a plurality of power states by asserting a signal to a keyboard controller which, in turn, transmits a command to the second graphics controller, said command dictating the particular power state for the second graphics controller.

23. The system of claim 15 wherein the control logic comprises a keyboard controller.

24. A system, comprising:

a first graphics means for providing graphics signals to a first display;

a second graphics means for providing graphics signals to a removable second display via a connector;

means for disabling power to said second graphics means if the second display is not coupled to said connector.

27. The method of claim 24 further comprising:

if the second display is connected to the system, enabling communications to the second graphics controller; and

if the second display is not connected to the system, disabling communications to the second graphics controller.

25. A method, comprising:

determining whether a second display is connected to a system that also comprises a first display, said first display being operated by a first graphics controller;

if the second display is connected to the system, causing power to be provided to the second graphics controller; and

if the second display is not connected to the system, causing power to be off to the second graphics controller.

26. The method of claim 25 further comprising maintaining power to the first graphics controller while disabling power from the second graphics controller.

28. A method, comprising:

determining whether a second display is connected to a system that also comprises a first display, said first display being operated by a first graphics controller;

if the second display is connected to the system, causing a second graphics controller, which is adapted to provide information to the second display for display thereon, to be in a fully operational state; and

if the second display is not connected to the system, causing the second graphics controller to be in a lower power state relative to the fully operational state.

29. The method of claim 28 further comprising transitioning the state of the second graphics controller between the fully operational state and lower power state depending on whether the second display is connected to the system during system run-time.