POWER STATE DEPENDENT WAKE-UP ALARM

• US 20100153765A1
• Filed: 12/16/2008
• Published: 06/17/2010
• Est. Priority Date: 12/16/2008
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Tao, Libo, Pierce, Tony, Liaw, Timothy W., Stemen, Patrick L., Judge, Nicholas S.
• Granted Patent: US 9,152,199 B2
• Time in Patent Office: Days
• US Class Current: 713/340
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode

Abstract

A method of operating a computing device to allow events to be conditionally executed based on a power state of the device at the time of execution of the events. Conditional execution may be implemented using multiple timers, each associated with a power state. A timer such as an “AC timer” or a “DC timer” associated with a respective power state may be used to wake up the device when, upon expiration, or time-out, of the timer, a current power state of the device and the power state associated with the timer match. An Advanced Configuration Power Interface (ACPI) may be employed to abstract implementation of the timers from underlying hardware of the device. The operating system and software applications may request establishing wake-up behavior of the device as commands to program conditional events, which may then be translated into commands to embedded controller to set the timers.

Claims

1. A method of operating a computing device comprising a plurality of timers each associated with a power state, the method comprising:

setting a first timer of the plurality of timers associated with a first power state, the first timer being configured, upon expiration, to cause the computing device to transition to a wake-up mode if a current power state of the computing device and the first power state match;

setting a second timer of the plurality of timers associated with a second power state, the second timer being configured, upon expiration, to cause the computing device to transition to the wake-up mode if the current power state of the computing device and the second power state match;

causing the computing device to transition to the wake-up mode when the first timer expires and the current power state of the computing device and the first power state match; and

causing the computing device to transition to the wake-up mode when the second timer expires and the current power state of the computing device and the second power state match.

2. The method of claim 1, wherein:

the first power state comprises an AC power state and the first timer comprises a timer that causes the computing device to transition to the wake-up mode if the computing device is operating using an AC power source; and

the second power state comprises a DC power state and the second timer comprises a timer that causes the computing device to transition to the wake-up mode if the computing device is operating using a DC power source.

3. The method of claim 1, wherein the computing device transitions to the wake-up mode from a first sleep mode to transition to a second sleep mode.

4. The method of claim 3, wherein the second sleep mode comprises a state wherein the computing device consumes less power than when in the first sleep mode.

5. The method of claim 1, wherein the first and second timers are virtual timers based on a same physical timer.

6. The method of claim 1, wherein setting the first and second timers comprises issuing commands through an Advanced Configuration and Power Interface (ACPI).

7. The method of claim 1, wherein the first and second timers are used to control operation of a Real-Time Clock (RTC) alarm.

8. The method of claim 1, comprising:

when the first timer expires and the computing device is operating using the second power source, resetting the first timer; and

when the second timer expires and the computing device is operating using the first power source, resetting the second timer.

9. The method of claim 1, wherein the first and second timers are set when the computing device transitions to a sleep mode.

10. The method of claim 1, further comprising:

when the first timer is set and a power source of the computing device switches from the first power source to the second power source, stop operating the first timer until the power source switches from the second power source to the first power source; and

when the second timer is set and the power source switches from the second power source to the first power source, stop operating the second timer until the power source switches from the first power source to the second power source.

11. A computing device configured to operate using multiple power sources, the computing device comprising:

at least one timer;

a computer storage medium encoded with computer-executable instructions implementing an operating system, the operating system being adapted to receive at least one request for establishing wake-up behavior based on an associated power state, and, in response to the at least one request, generate a command that sets a timer of the at least one timer and store information defining the requested wake-up behavior; and

a controller adapted to, upon time-out of the set timer, compare a current power state of the computing device to the associated power state of the requested wake-up behavior in the stored information and cause the computing device to transition to a wake-up mode when the current power state and the associated power state match.

12. The computing device of claim 11, further comprising a power supply controller providing information on the current power state to the controller.

13. The computing device of claim 11, wherein the operating system is further adapted to generate commands to program the controller through an Advanced Configuration and Power Interface.

14. The computing device of claim 11, wherein the at least one request comprises:

at least one request for setting a first timer configured, upon expiration, to cause the computing device to transition to the wake-up mode if the computing device is operating using a first power source; and

at least one request for setting a second timer configured, upon expiration, to cause the computing device to transition to the wake-up mode if the computing device is operating using a second power source.

15. The computing device of claim 14, wherein

the first power state comprises an AC power state and the first timer comprises a timer that causes the computing device to transition to the wake-up mode if the computing device is operating using an AC power source;

and

the second power state comprises a DC power state and the second timer comprises a timer that causes the computing device to transition to the wake-up mode if the computing device is operating using a DC power source.

16. A controller configured to perform a method of controlling a computing device, the method comprising:

obtaining, from an operating system of the computing device, at least one timer of a plurality of timers each associated with a power state;

obtaining an indication of a current power state of the computing device;

determining, upon time-out of the at least one timer, whether the power state associated with the at least one timer and the current power state match; and

waking up the computing device from a sleep mode when the associated power state and the current power state match.

17. The controller of claim 16, wherein the at least one timer comprises:

a first timer associated with an AC power state that, upon time-out, causes the computing device to wake up when the computing device is operating using an AC power source; and

a second timer associated with a DC power state that, upon time-out, causes the computing device to wake up when the computing device is operating using a DC power source.

18. The controller of claim 16, wherein, when, upon time-out of the at least one timer, the power state of the computing device is different from the power state associated with the at least one, resetting the at least one timer.

19. The controller of claim 16, wherein the operating system comprises an ACPI-compliant operating system.

20. The controller of claim 16, wherein the at least one timer is used to wake up the computing device more than 24 hours after the at least one timer has been started.