System for reduced power consumption by monitoring video content and method thereof

• US 20030128198A1
• Filed: 02/27/2002
• Published: 07/10/2003
• Est. Priority Date: 01/04/2002
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Inventors: Leung, Charles, Aleksic, Milivoje, Mizuyabu, Carl
• Granted Patent: US 7,017,053 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• 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 1/3225 of memory devices
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• 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
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system and method are provided for reducing power consumption within a video processing portion of a system based on display content. Display content is monitored to determine whether the display content is changing. New display content is compared to old display content to determine if the display content is changing. If the display content has not changed, a frame rate used to output display data is reduced. A color depth associated with the display data is also reduced. Power consumption can be reduced when it is determined that display content is not changing.

Claims

1. A method comprising the steps of:

identifying a first display content to be displayed at a first time;

identifying a second display content to be displayed at a second time, wherein the second time is after the first time;

providing display data to a display port at a first frame rate, when the first display content is different from the second display content; and

providing display data to the display port at a second frame rate, when the first display content is substantially the same as the second display content, wherein the second frame rate is less than the first frame rate.

2. The method as in claim 1, further including the steps of:

enabling a first clock rate, when the first display content is different from the second display content; and

enabling a second clock rate, when the first display content is substantially the same as the second display content, wherein the second clock rate is less than the first clock rate.

3. The method as in claim 2, wherein the step of enabling the first clock rate includes:

providing a clock signal associated with an oscillator to a phase locked loop; and

providing a locked clock signal generated by the phase locked loop to a clock bus.

4. The method as in claim 3, further wherein the step of enabling the second clock rate includes:

disabling the phase locked loop; and

providing the clock signal associated with the oscillator to the clock bus.

5. The method as in claim 1, further including the steps of:

representing the display data using a first number of bits, when the first display content is different from the second display content; and

representing the display data using a second number of bits, when the first display content is substantially the same as the second display content, wherein the second number of bits is less than the first number of bits.

6. The method as in claim 5, wherein the number of bits is associated with a color depth.

7. The method as in claim 1, further including the steps of:

activating a first number of interface lines associated with the display port, when the first display content is different from the second display content; and

activating a second number of interface lines associated with the display port, when the first display content is substantially the same as the second display content, wherein the second number of control lines is less than the first number of control lines associated with the display port.

8. The method as in claim 7, wherein the interface lines include one of digital to analog converter input lines, transition minimized differential signaling input lines, or low voltage differential signaling input lines.

9. The method as in claim 1, further including the steps of:

identifying a third display content to be displayed at a third time, wherein the third time is after the second time;

providing display data with a first color depth, when the third display content is different from the first display content; and

providing display data with a second color depth, when the third display content is substantially the same as the first display content, when the second color depth is less than the first color depth.

10. The method as in claim 1, wherein the steps are performed within a portable device.

11. The method as in claim 10, wherein the portable device includes a personal digital assistant.

12. The method as in claim 1, wherein the display content is associated with a personal digital assistant.

13. The method as in claim 1, wherein the display data is for output on a display device.

14. The method as in claim 13, wherein the display device includes a screen associated with a personal digital assistant.

15. The method as in claim 14, wherein the display device includes a liquid crystal display.

16. The method as in claim 1, further including the steps of:

supporting a first nominal power, when the first display content is different from the second display content; and

supporting a second nominal power, when the first display content is substantially the same as the second display content, wherein the second nominal power is less than the first nominal power.

17. The method as in claim 1, wherein a number of bits used to represent multimedia data is changed to match a change in nominal power.

18. The method as in claim 17, wherein the multimedia data includes video data.

19. The method as in claim 17, wherein the multimedia data includes audio data.

20. A method comprising the steps of:

identifying a first display content to be displayed at a first time;

identifying a second display content to be displayed at a second time, wherein the second time is after the first time;

using a first number of bits to represent display data, when the first display content is different from the second display content; and

using a second number of bits to represent display data, when the first display content is substantially the same as the second display content, wherein the second frame rate is less than the first frame rate.

21. The method as in claim 20, wherein the number of bits used to represent data includes a color depth.

22. The method as in claim 20, wherein the display data is for display on a display device.

23. The method as in claim 22, wherein the display device includes a personal digital assistant screen.

24. The method as in claim 20, further including the steps of:

enabling a first clock rate, when the first display content is different form the second display content; and

enabling a second clock rate, when the first display content is substantially the same as the second display content, wherein the second clock rate is less than the first clock rate.

25. The method as in claim 24, wherein the step of enabling the first clock rate includes:

providing a clock signal associated with an oscillator to a phase locked loop; and

providing a locked clock signal generated by the phase locked loop to a clock bus.

26. The method as in claim 25, further wherein the step of enabling the second clock rate includes:

disabling the phase locked loop; and

providing the clock signal associated with the oscillator to the clock bus.

27. The method as in claim 20, further including the steps of:

supporting a first nominal power, when the first display content is different from the second display content; and

supporting a second nominal power, when the first display content is substantially the same as the second display content, wherein the second nominal power is less than the first nominal power.

28. A system comprising:

a content analyzer to compare a first display content to be displayed at a first time with a second display content to be displayed at a second time, wherein the second time is after the first time;

a display module to alter a frame rate for providing display data to a display port, wherein said frame rate is based on the comparison performed by said content analyzer; and

said display port to output said display data.

29. The system as in claim 28, wherein said display module further used to:

apply a first frame rate for providing display data to said display port, when said content analyzer determines the first display content is different from the second display content; and

apply a second frame rate for providing display data to said display port, when said content analyzer determines the first display content is substantially the same as the second display content, wherein the second frame rate is less than the first frame rate.

30. The system as in claim 28, wherein said first display content is stored in memory.

31. The system as in claim 28, further including a power module, said power module to:

enable a first clock rate, when said content analyzer determines the first display content is different from the second display content; and

enable a second clock rate, when said content analyzer determines the first display content is substantially the same as the second display content, wherein said second clock rate is less than said first clock rate.

32. The system as in claim 28, further including a power module, said power module to:

support a first nominal power, when said content analyzer determines the first display content is different from the second display content; and

support a second nominal power when said content analyzer determines the first display content is substantially the same as the second display content, wherein said second nominal power is less than said first nominal power.

33. The system as in claim 28, wherein:

said content analyzer further used to compare a third display content to be displayed at a third time with the first display content, wherein the third time is after the second time; and

said display module further to;

provide display data with a first color depth, when the content analyzer determines the third display content is different from the first display content; and

provide display data with a second color depth, when the content analyzer determines the third display content is substantially the same as the first display content.

34. A system comprising:

a content analyzer to compare a first display content to be displayed at a first time with a second display content to be displayed at a second time, wherein the second time is after the first time;

a display module to alter a number of bits used to represent display data, wherein said number of bits is based on the comparison performed by said content analyzer; and

said display port to output said display data.

35. The system as in claim 34, wherein said display module further used to:

apply a first number of bits used to represent display data, when said content analyzer determines said first display content is different from said second display content;

apply a second number of bits used to represent display data, when the first display content is substantially the same as the second display content, wherein the second number of bits used to represent display data is less than the first number of bits used to represent display data.

36. The system as in claim 34, wherein the number of bits used to represent data is associated with a color depth of the display data.

37. The system as in claim 34, wherein said display port is coupled to one of a digital to analog converter, a transition minimized differential signaling transceiver, or a low voltage differential signaling transceiver, for providing display data to a display device.

38. The system as in claim 37, wherein said display device includes a screen of a personal digital assistant.

39. The system as in claim 38, wherein said display device includes a liquid crystal display.

40. The system as in claim 34, further including a power module, said power module to:

enable a first clock rate, when said content analyzer determines the first display content is different from the second display content; and

enable a second clock rate, when said content analyzer determines the first display content is substantially the same as the second display content, wherein said second clock rate is less than said first clock rate.

41. The system as in claim 34, further including a power module, said power module to:

support a first nominal power, when said content analyzer determines the first display content is different from the second display content; and

support a second nominal power when said content analyzer determines the first display content is substantially the same as the second display content, wherein said second nominal power is less than said first nominal power.