System for providing multiple display support and method thereof

• US 6,970,173 B2
• Filed: 09/14/2001
• Issued: 11/29/2005
• Est. Priority Date: 09/14/2001
• Status: Expired due to Term

• Current Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Original Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Inventors: Ciolac, Alec A.
• Primary Examiner(s): Tung, Kee M.
• Application Number:
  US09/954,685
• Publication Number:
  US 20030048275A1
• Time in Patent Office: 1,537 Days
• Field of Search: 345501-506, 345519-520, 345/522, 345530-574, 345/778, 345 11- 34
• US Class Current: 345/544
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 5/14 Display of multiple viewports
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

A system and method is provided for supporting a multiple display configuration through a single connected display device. The present disclosure allows a system desktop to be expanded across multiple virtual displays without a need for extra hardware to support multiple display devices. A display driver partitions a frame buffer of a video card into portions. Each portion is used to support a different virtual display. The display driver reports a number of virtual displays to an operating system and provides pointers to addresses associated with the portions of the frame buffer. The operating system treats each frame buffer portion as a separate frame buffer and stores video data for each virtual display in an associated frame buffer portion. The display driver selects a virtual display from a set of multiple virtual displays and routes video data from the frame buffer portion associated with the selected display for output on a connected display device.

Claims

1. A method comprising

partitioning a frame buffer into a first portion and a second portion associated with a first virtual display and a second virtual display, wherein a space allocated to at least the first portion is based on one or more parameters of at least the first virtual display;

storing a first set of display data in the first portion of the frame buffer, wherein the first set of display data is associated with the first virtual display;

storing a second set of display data in the second portion of the frame buffer, wherein the second set of display data is associated with the second virtual display;

selecting one of the first virtual display or the second virtual display to be presented by a display device;

when the first virtual display is selected, providing data from the first portion of the frame buffer to a display controller for presentation on the display device; and

when the second virtual display is selected, providing data from the second portion of the frame buffer to the display controller for presentation on the display device.

2. The method as in claim 1, wherein the frame buffer is associated with video hardware connected to the display device.

3. The method as in claim 1, wherein selecting one of the first virtual display or the second virtual display includes identifying an event trigger.

4. The method as in claim 3, wherein the event trigger includes identifying a particular first pre-defined set of keystrokes to select the first virtual display and a second pre-defined set of keystrokes to select the second virtual display.

5. The method as in claim 3, wherein the event trigger includes a mouse position.

6. The method as in claim 3, wherein the event trigger includes activity associated with an application on one of the first virtual display or the second virtual display.

7. The method as in claim 1, wherein an operating system desktop is expanded over the first and second virtual displays.

8. The method as in claim 1, wherein the first set of display data is associated with a first application and the second set of display data is associated with a second application, the first application being different than the second application, and the first application not being associated with the second application.

9. The method as in claim 1, wherein the one or more parameters include a resolution assigned to the first virtual display.

10. The method as in claim 1, wherein the one or more parameters include a color depth assigned to the first virtual display.

11. A method comprising:

determining a number of virtual displays in a plurality of virtual displays to be supported;

partitioning a frame buffer into a plurality of frame buffer portions, wherein the plurality of frame buffer portions includes a first frame buffer portion associated with a first virtual display of the plurality of virtual displays and a second frame buffer portion associated with a second virtual display of the plurality of virtual displays;

reporting the number of virtual displays as a number of display devices;

providing a first address associated with the first frame buffer portion, wherein the first address is reported as an address of a first frame buffer associated with a first display device; and

providing a second address associated with the second frame buffer portion, wherein the second address is reported as an address of a second frame buffer associated with a second display device;

wherein at any given time, only one of the number of virtual displays is to be displayed.

12. The method as in claim 11, further including:

selecting one of the first virtual display or the second virtual display;

when the first virtual display is selected, providing data associated with the first frame buffer portion; and

when the second virtual display is selected, providing data associated with the second frame buffer portion.

13. The method as in claim 12, wherein selecting one of the first virtual display or the second virtual display includes identifying a vent trigger.

14. The method as in claim 13, wherein the event trigger includes identifying a particular first pre-defined set of keystrokes to select first virtual display and a second pre-defined set of keystrokes to select the second virtual display.

15. The method as in claim 13, wherein the event trigger includes a mouse position.

16. The method as in claim 13, wherein the event trigger includes an activity associated with an application displayed on one of the first virtual display or the second virtual display.

17. The method as in claim 11, wherein partitioning the frame buffer includes determining a space to assign to a portion of the frame buffer dependent on parameters of an associated virtual display.

18. A The method as in claim 17, wherein the parameters include a resolution assigned to each virtual display.

19. The method as in claim 17, wherein the parameters include a color depth assigned to each of the virtual displays.

20. The method as in claim 11, wherein the number of display devices to be supported is based on an available size of the frame buffer.

21. The method as in claim 11, wherein the number of display devices to be supported is based on virtual display parameters.

22. The method as in claim 21, wherein the parameters include a resolution assigned to each virtual display.

23. The method as in claim 21, wherein the parameters include a color depth assigned to each of the virtual displays.

24. The method as in claim 11, wherein reporting the number of virtual displays includes providing the number of virtual displays to an operating system as the number of display devices in a multiple display configuration.

25. A system comprising:

a data processor having an input/output buffer;

memory having an input/output buffer coupled to the input/output buffer of the data processor, said memory having a program of instructions including;

a display driver to;

report a multiple display configuration, wherein said multiple display configuration includes support for a plurality of virtual displays;

partition a frame buffer into a plurality of frame buffer portions;

assign a different virtual display of the plurality of virtual displays to each of the frame buffer portions of the plurality of frame buffer portions;

a video controller coupled to the input/output buffer of the data processor, said video controller having;

a frame buffer having the plurality of frame buffer portions, wherein each frame buffer portion of the plurality of frame buffer portions is to store display data associated with an assigned virtual display of the plurality of virtual displays; and

a display controller to provide display data from a frame buffer portion of the plurality of frame buffer portions to a display device; and

wherein said display controller is to display a selected virtual display from the plurality of virtual displays dependent on an event trigger.

26. The system as in claim 25, wherein said display driver further is to select a virtual display from the plurality of virtual displays for presentation and said display data provided by said display controller is associated with the selected virtual display.

27. The system as in claim 26, wherein the event trigger includes identifying a particular first pre-defined set of keystrokes to select a first virtual display of the plurality of virtual displays and a second pre-defined set of keystrokes to select a second virtual display of the plurality of virtual displays.

28. The system as in claim 26, wherein the event trigger includes a mouse position.

29. The system as in claim 26, wherein the event trigger includes an activity associated with an application displayed on one of the virtual displays of the plurality of virtual displays.

30. The system as in claim 25, wherein said display driver reports said multiple display configuration to an operating system.

31. A computer readable medium tangibly embodying a program of instructions, said program of instructions including instructions to:

determine a number of virtual displays in a plurality of virtual displays to be supported;

partition a frame buffer into a plurality of frame buffer portions, wherein the plurality of frame buffer portions include a first frame buffer portion associated with a first virtual display of the plurality of virtual displays and a second frame buffer portion associated with a second virtual display of the plurality of virtual displays;

report the number of virtual displays as a number of display devices in a multiple display configuration;

provide a first address associated with the first frame buffer portion, wherein the first address is reported as an address of a first frame buffer associated with a first display device of the multiple display configuration; and

provide a second address associated with the second frame buffer portion, wherein the second address is reported as an address of a second frame buffer associated with a second display device of the multiple display configuration;

wherein at any given time, only one of the number of virtual displays is to be displayed.

32. The computer readable medium as in claim 31, further including instructions to:

select one of the first virtual display or the second virtual display;

provide data associated with the first frame buffer portion when the first virtual display is selected; and

provide data associated with the second frame buffer portion when the second virtual display is selected.

33. The computer readable medium as in claim 32, wherein a trigger event is used to select one of the first virtual display or the second virtual display.

34. The computer readable medium as in claim 33, wherein the event trigger includes identifying a particular first pre-defined set of keystrokes to select the first virtual display and a second pre-defined set of keystrokes to select the second virtual display.

35. The computer readable medium as in claim 33, wherein the event trigger includes a mouse position.

36. The computer readable medium as in claim 33, wherein the event trigger includes an activity associated with an application displayed on one of the first virtual display or the second virtual display.

37. The computer readable medium as in claim 31, wherein the instructions to partition the frame buffer includes determining a space to assign to a portion of the frame buffer dependent on parameters of an associated virtual display.

38. The computer readable medium as in claim 37, wherein the parameters include a resolution assigned to each virtual display.

39. The computer readable medium as in claim 37, wherein the parameters include a color depth assigned to each of the virtual displays.

40. The computer readable medium as in claim 31, wherein the number of display devices to be supported is based on an available size of the frame buffer.

41. The computer readable medium as in claim 31, wherein the number of display devices to be supported is based on virtual display parameters.

42. The computer readable medium as in claim 41, wherein the parameters include a resolution assigned to each virtual display.

43. The computer readable medium as in claim 31, wherein the instructions to report the number of virtual displays includes instructions to report the multiple display configuration to an operating system.