Forced idle of a data processing system

• US 7,949,888 B2
• Filed: 01/07/2008
• Issued: 05/24/2011
• Est. Priority Date: 01/07/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Conroy, David G., Culbert, Michael, Cox, Keith
• Primary Examiner(s): Knoll; Clifford H
• Application Number:
  US11/970,476
• Publication Number:
  US 20090177422A1
• Time in Patent Office: 1,233 Days
• Field of Search: 713300-324, 323/234
• US Class Current: 713/323
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Exemplary embodiments of methods and apparatuses to manage a power of a data processing system are described. A constraint parameter of a system operating at a first frequency and a first voltage is monitored. The system is, based on the monitoring of the constraint parameter, forced into an idle state while operating at a second frequency and a second voltage. The idle state prevents instructions from being executed.

Claims

1. A machine-implemented method, comprising:

monitoring a constraint parameter of a system operating at a first frequency and a first voltage, the first voltage applied to a voltage input of the system from a power supply;

forcing the system into an idle state in which instructions are prevented from being executed by at least decreasing, at the voltage input, the first voltage to a voltage below a second voltage based on the monitoring of the constraint parameter.

2. The machine-implemented method of claim 1 wherein the system is forced into the idle state while the system continues to operate at a second frequency that is less than the first frequency.

3. The machine-implemented method of claim 1, further comprising:

determining a rate of forcing the system into the idle state.

4. The machine-implemented method of claim 1, wherein the second voltage is a minimum voltage, the method further comprising:

determining whether the constraint parameter is greater than a constraint parameter threshold;

determining whether the first voltage is decreased to the second voltage; and

forcing the system into the idle state if the first voltage is decreased to the second voltage and the constraint parameter is greater than the constraint parameter threshold.

5. The machine-implemented method of claim 4, further comprising:

decreasing an operating point of the system if the system does not operate at the minimum voltage and the constraint parameter is greater than the constraint parameter threshold.

6. The machine-implemented method of claim 1, wherein the constraint parameter is a power, a temperature, a current, a battery load, or any combination thereof and wherein the system continues to operate at a second frequency that is greater than zero and is less than the first frequency and wherein the second voltage is greater than zero and is less than the first voltage.

7. The machine-implemented method of claim 1, further comprising:

determining a percentage of the idle state for the system operating at the first frequency and the first voltage based on the constraint parameter and wherein the first frequency is decreased to zero the first voltage is decreased to zero for at least a portion of the system.

8. A data processing system, comprising:

a processor,

a memory, coupled to the processor;

one or more sensors coupled to the processor to monitor a constraint parameter of a system operating at a first frequency and a first voltage, the first voltage applied to a voltage input of the system from a power supply wherein the processor is configured to force the system into an idle state in which instructions are prevented from being executed by at least decreasing, at the voltage input, the first voltage to a voltage below an operating voltage based on monitoring of the constraint parameter.

9. The data processing system of claim 8, wherein the system is forced into the idle state while the system continues to operate at a second frequency that is less than the first frequency.

10. The data processing system of claim 8, wherein the processor is further configured to

determine a rate of forcing the system into the idle state.

11. The data processing system of claim 8, wherein the second voltage is a minimum voltage and wherein the processor is further configured to

determine whether the constraint parameter is greater than a constraint parameter threshold, determine whether the first voltage is decreased to the second voltage, and force the system into the idle state if the first voltage is decreased to the second voltage and the constraint parameter is greater than the constraint parameter threshold.

12. The data processing system of claim 11, wherein the processor is further configured to

decrease an operating point of the system if the system does not operate at the minimum voltage and the constraint parameter is greater than the constraint parameter threshold.

13. The data processing system of claim 8, wherein the processor is further configured to

determine a percentage of the idle state for the system operating at the first frequency and the first voltage based on the constraint parameter and wherein the first frequency is decreased to zero and the first voltage is decreased to zero for at least a portion of the processor.

14. The data processing system of claim 8, wherein the memory stores information about when and how to force the system into the idle state.

15. The data processing system of claim 8, wherein the constraint parameter is a power, a temperature, a current, a battery load, or any combination thereof and wherein the second frequency is greater than zero and is less than the first frequency and wherein the second voltage is greater than zero and is less than the first voltage.

16. A machine-readable storage medium storing executable program instructions which cause a data processing system to perform operations comprising:

monitoring a constraint parameter of the system operating at a first frequency and a first voltage, the first voltage applied to a voltage input of the system from a power supply;

forcing the system into an idle state in which instructions are prevented from being executed by at least decreasing, at the voltage input, the first voltage to a voltage below an operating voltage based on the monitoring of the constraint parameter.

17. The machine-readable medium of claim 16, wherein the system is forced into the idle state while the system continues to operate at a second frequency that is less than the first frequency.

18. The machine-readable medium of claim 16, further including instructions that cause the data processing system to perform operations comprising:

determining a rate of forcing the system into the idle state.

19. The machine-readable medium of claim 16, wherein the second voltage is a minimum voltage and wherein the machine-readable medium further including instructions that cause the data processing system to perform operations comprising:

determining whether the constraint parameter is greater than a constraint parameter threshold;

determining whether the first voltage is decreased to the minimum voltage; and

forcing the system into the idle state if the first voltage is decreased to the second voltage and the constraint parameter is greater than the constraint parameter threshold.

20. The machine-readable medium of claim 19, further including instructions that cause the data processing system to perform operations comprising:

decreasing an operating point of the system if the system does not operate at the minimum voltage and the constraint parameter is greater than the constraint parameter threshold.

21. The machine-readable medium of claim 16, further including instructions that cause the data processing system to perform operations comprising:

determining a percentage of the idle state for the system operating at the first frequency and the first voltage based on the constraint parameter and wherein the first frequency is decreased to zero and the first voltage is decreased to zero for at least a portion of the system.

22. The machine-readable medium of claim 16, wherein the constraint parameter is a power, a temperature, a current, a battery load, or any combination thereof and wherein the second frequency is greater than zero and is less than the first frequency and wherein the second voltage is greater than zero and is less than the first voltage.

23. A data processing system, comprising:

means for monitoring a constraint parameter of the system operating at a first frequency and a first voltage, the first voltage applied to a voltage input of the system from a power supply;

means for forcing the system into an idle state in which instructions are prevented from being executed by at least decreasing, at the voltage input, the first voltage to a voltage below a second voltage based on the monitoring of the constraint parameter.

24. The data processing system of claim 23, wherein the second voltage is a minimum voltage, the data processing system further comprising:

means for determining whether the constraint parameter is greater than a constraint parameter threshold;

means for determining whether the first voltage is decreased to the second voltage; and

means for forcing the system into the idle state if the first voltage is decreased to the second voltage and the constraint parameter is greater than the constraint parameter threshold.

25. The data processing system of claim 23, further comprising:

means for determining a percentage of the idle state for the system operating at the first frequency and the first voltage based on the constraint parameter, and wherein the second frequency is greater than zero and is less than the first frequency and wherein the second voltage is greater than zero and is less than the first voltage.