Method and system for operating a portable electronic device in a power-limited manner

• US 7,541,776 B2
• Filed: 12/10/2004
• Issued: 06/02/2009
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Tupman, David John, Bollinger, Steven
• Primary Examiner(s): Ullah; Akm E
• Assistant Examiner(s): Muralidar; Richard V
• Application Number:
  US11/009,675
• Publication Number:
  US 20060125446A1
• Time in Patent Office: 1,635 Days
• Field of Search: 320/132, 320134-136, 307 43- 46, 307 64- 66
• US Class Current: 320/134
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

Improved techniques to manage operation of a portable electronic device having a substantially depleted battery when power is available from an external, power-limited source are disclosed. In one embodiment of the invention, the substantially depleted battery can be initially charged while a power-intensive operation is delayed. Once the battery has adequate charge to assist the external, power-limited source in powering the portable electronic device, the power-intensive operation can be performed. In this manner, power consumption of a portable electronic device can be managed so that reliable operation is achieved without exceeding limits on power being drawn from an external, power-limited source.

Claims

1. A method for starting up a mobile device having a battery, said method comprising:

(a) examining a battery level of the battery;

(b) determining whether the battery level is substantially depleted;

(c) determining whether an external, power-limited power source is electrically coupled to the mobile device;

(d) deferring start-up of the mobile device while charging the battery via power provided to the mobile device from the external, power-limited power source when said determining (b) determines that the battery level is substantially depleted and said determining (c) determines that the external, power-limited power source is electrically coupled to the mobile device;

(d1) after a delay imposed by the charging during said deferring (d) of start-up of the mobile device, determining whether the battery level is at least adequate to assist the external, power-limited power source to at least achieve successful start-up of the mobile device;

(d2) halting charging of the battery when the determining (d1) determines that the battery level is at least adequate to assist the external, power-limited power source to at least achieve successful start-up of the mobile device, wherein said battery level is less than fully charged; and

(d3) starting-up of the mobile device using power from the battery and the power provided to the mobile device from the external, power limited power source.

2. A method as recited in claim 1, wherein the mobile device includes a display screen, and

wherein said method further comprises:

(e) displaying a low power indication on the display screen while staff-up of the mobile device is deferred by said deferring (d).

3. A method as recited in claim 1, wherein the external, power-limited source is a peripheral bus that couples to the mobile device and from which a reduced amount of power may be drawn or an increased amount of power may be drawn.

4. A method as recited in claim 3, wherein said method comprises:

(e) negotiating for increased power consumption via the power-limited source after completing start-up of the mobile device so as to be approved to draw more than the reduced amount of power but not more than the increased amount of power from the peripheral bus.

5. A method as recited in claim 3,

wherein said performing (d3) starting-up of the mobile device does not draw more than the reduced amount of power from the peripheral bus, and any additional power needs for (d3) starting-up of the mobile device are supplied by the battery.

6. A method as recited in claim 1, wherein the mobile device is a portable media player having a data storage device that stores media items.

7. A method as recited in claim 1, wherein the mobile device is a mobile telephone or a personal digital assistant.

8. A method for starting up a mobile computing device having a battery, said method comprising:

(a) examining a battery level of the battery;

(b) determining whether the battery level exceeds a first threshold level;

(c) determining whether power is available from a host computer via a power-limited peripheral bus electrically coupled to the mobile computing device;

(d) initiating charging of the battery using at least a portion of the power that is available via the power-limited peripheral bus when said determining (b) determines that the battery level does not exceed the first threshold level and said determining (c) determines that power is available from the power-limited peripheral bus;

(e) examining the battery level of the battery;

(f) determining, following said charging (d) and said examining (e), whether the battery level at least meets a second threshold level, wherein said second threshold level is less than fully charged;

(f1) halting charging of the battery when the battery level is determined to at least meet the second threshold; and

(g) initiating start-up of the mobile computing device after said determining (f) determines that the battery level exceeds the second threshold level using power from the battery and the power provided to the mobile device from the external, power limited peripheral bus.

9. A method as recited in claim 8, wherein the mobile computing device includes a display screen, and wherein said method further comprises:

displaying a low power indication on the display screen when said determining (b) determines that the battery level does not exceed the first threshold level and said determining (c) determines that power is not available from the power-limited peripheral bus.

10. A method as recited in claim 8, wherein start-up of the mobile computing device does not draw more than a predetermined reduced amount of power from the peripheral bus.

11. A method as recited in claim 10, wherein the battery supplies additional power for start-up of the mobile computing device when staff-up of the mobile computing device requires an amount of power greater than the predetermined reduced amount of power permitted to be drawn from the peripheral bus.

12. A method as recited in claim 11, wherein said method further comprises:

negotiating for increased power consumption via the power-limited peripheral bus after completing staff-up of the mobile computing device.

13. A method as recited in claim 8, wherein said method further comprises:

negotiating for increased power consumption via the power-limited peripheral bus after completing staff-up of the mobile computing device.

14. A method as recited in claim 13, wherein said method further comprises:

displaying a low power indication on the display screen when said negotiating does not successfully negotiate for the increased power consumption.

15. The method as recited in claim 8, wherein said determining (b) determines whether stored energy in the battery is substantially depleted.

16. A method as recited in claim 8, wherein the mobile device is a handheld media player having a data storage device that stores media items.

17. A method as recited in claim 16, wherein the media items are audio files that can be played by the handheld media player.

18. A method as recited in claim 8, wherein the mobile computing device is a mobile telephone or a personal digital assistant.

19. A method as recited in claim 8, wherein the first threshold level equals the second threshold level.

20. A media device, comprising:

a media store for storing media items;

a communication interface for interfacing with a host device via a cable that provides media data and power to said media device when the cable is connected between said media device and the host device;

a battery for providing power to said media device;

a battery charging circuit for providing charging current to the battery; and

a battery monitor that monitors a battery attribute of said battery used by the battery charging circuit to provide charging current, or not, to the battery,

wherein start-up of the media device is deferred based on the battery attribute of said battery as monitored by said battery monitor; and

wherein the charging of the battery is halted by disabling the battery charging circuit prior to the commencement of and during start-up of the media device when the monitored battery attribute reaches a level sufficient to successfully complete start-up of the device in combination with power provided to start-up the device by the cable.

24. A media device as recited in claim 20, said media device further comprising:

a display screen that displays a low power indication on the screen when the monitored battery attribute is below that sufficient to successfully complete start-up of the device.

25. A media device as recited in claim 20 wherein the battery attribute is the charge level of the battery.

26. A media device as recited in claim 20 wherein the host device includes a power limited source connected to the media device by way of the cable, wherein the power limited source is capable of providing a reduced amount of power or an increased amount of power via the cable to the media device.

27. A media device as recited in claim 26 wherein, after the media device is started up, the host device and the media device negotiate to determine whether the reduced amount of power or the increased amount of power is provided to the media device.

28. A media device as recited in claim 27 wherein the starting-up of the media device does not require more that the reduced amount of power and any additional power needs for starting-up of the mobile device are supplied by the battery.

29. A media device as recited in claim 20 wherein the media device is a mobile telephone or a personal digital assistant.

21. A computer readable medium for storing a computer program executable by a processor for performing a start-up operation by a mobile device having a battery, said computer program readable medium comprising:

computer program code for examining a battery level of the battery;

computer program code for determining whether the battery level is substantially depleted;

computer program code for determining whether a power-limited power source is electrically coupled to the mobile device;

computer program code for deferring performance of the start-up operation by the mobile device while charging the battery via power provided to the mobile device from the power-limited power source when it is determined that the battery level is substantially depleted and it is determined that the power-limited power source is electrically coupled to the mobile device;

computer program code for halting charging of the battery after a delay imposed by the charging and when it is determined that the battery level becomes at least adequate to assist the power-limited power source to at least achieve successful completion of the start-up operation by the mobile device, wherein said battery level is below fully charged; and

computer program code for performing the start-up operation by the mobile device.

22. A computer readable medium as recited in claim 21,

wherein the power-limited source is a peripheral bus that couples to the mobile device and from which a reduced amount of power may be drawn or an increased amount of power may be drawn, and

wherein start-up of the mobile device does not draw more than the reduced amount of power from the peripheral bus.

23. A computer readable medium as recited in claim 22, wherein said computer readable medium further comprises:

computer program code for negotiating for increased power consumption via the power-limited source after completing the start-up operation by the mobile device so as to be approved to draw more than the reduced amount of power but not more than the increased amount of power from the peripheral bus.