Frequency specific closed loop feedback control of integrated circuits

• US 8,040,149 B2
• Filed: 09/01/2009
• Issued: 10/18/2011
• Est. Priority Date: 04/16/2002
• Status: Expired due to Fees

• Current Assignee: Meta Platforms, Inc. (f/k/a Facebook, Inc.)
• Original Assignee: Intellectual Ventures Funding LLC (Intellectual Ventures LLC)
• Inventors: Koniaris, Kleanthes G., Burr, James B.
• Primary Examiner(s): Hollington, Jermele M
• Application Number:
  US12/552,243
• Publication Number:
  US 20100060306A1
• Time in Patent Office: 777 Days
• Field of Search: None
• US Class Current: 324/762.01
• CPC Class Codes: G01R 31/2621 for testing field effect transistors, i.e. FET's
• CPC Class Codes: G05B 13/021 in which a variable is automatically adjusted to optimise the performance
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• 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: H03K 3/012 Modifications of generator to improve response time or to decrease power consumption
• CPC Class Codes: H03K 3/0315 Ring oscillators
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Systems and methods for frequency specific closed loop feedback control of integrated circuits. In one embodiment, a plurality of controllable inputs to an integrated circuit is adjusted to achieve a frequency specific predetermined value of a dynamic operating indicator of the integrated circuit at the desired specific operating frequency. The predetermined value is stored in a data structure within a computer usable media. The data structure comprises a plurality of frequency specific predetermined values for a variety of operating frequencies. An operating condition of an integrated circuit is controlled via closed loop feedback based on dynamic operating indicators of the measured behavior of the integrated circuit.

Claims

1. A method of operating an integrated circuit, said method comprising:

accessing a predetermined value of an operating characteristic of said integrated circuit, wherein said predetermined value correlates to a target value for an operating frequency of said integrated circuit;

measuring a current value of said operating characteristic; and

adjusting a voltage supply to provide a level of voltage to said integrated circuit to cause said current value of said operating characteristic to approach said predetermined value to cause said operating frequency to approach said target value.

2. The method of claim 1 further comprising:

repeating said measuring and said adjusting.

3. The method of claim 1, wherein said voltage supply is selected from a group consisting of:

a variable voltage supply operable to provide an operating voltage to said integrated circuit; and

a variable voltage supply operable to provide a body biasing voltage to said integrated circuit.

4. The method of claim 1, wherein said predetermined value comprises a frequency specific predetermined dynamic operating indicator value, and wherein said accessing further comprises accessing said predetermined value from a computer usable media.

5. The method of claim 1, wherein said accessing further comprises accessing said predetermined value from a data structure comprising a plurality of predetermined values, and wherein each of said plurality of predetermined values is associated with a respective operating frequency.

6. The method of claim 1, wherein said operating characteristic comprises at least one characteristic selected from a group consisting of:

a temperature of said integrated circuit;

a gate delay of said integrated circuit;

an off current of said integrated circuit;

a gate leakage of said integrated circuit; and

a behavior of a device selected from a group consisting of at least one NMOS device of said integrated circuit and at least one PMOS device of said integrated circuit.

7. A system comprising:

a first circuit component configured to measure a current value of an operating characteristic of an integrated circuit;

a second circuit component coupled to said first circuit component, wherein said second circuit component is configured to adjust a voltage supply to provide a level of voltage to said integrated circuit to cause said current value of said operating characteristic to approach a predetermined value of said operating characteristic, wherein said predetermined value correlates to a target value for an operating frequency of said integrated circuit and wherein said operating frequency approaches said target value in response to said operating characteristic approaching said predetermined value.

8. The system of claim 7, wherein said second circuit comprises a feedback loop.

9. The system of claim 7, wherein said voltage supply is selected from a group consisting of:

a variable voltage supply operable to provide an operating voltage to said integrated circuit; and

a variable voltage supply operable to provide a body biasing voltage to said integrated circuit.

10. The system of claim 7, wherein said predetermined value comprises a frequency specific predetermined dynamic operating indicator value, and wherein said predetermined value is accessed from a computer usable media.

11. The system of claim 7, wherein said predetermined value is stored in a data structure comprising a plurality of predetermined values, and wherein each of said plurality of predetermined values is associated with a respective operating frequency.

12. The system of claim 7, wherein said operating characteristic comprises at least one characteristic selected from a group consisting of:

a temperature of said integrated circuit;

a gate delay of said integrated circuit;

an off current of said integrated circuit;

a gate leakage of said integrated circuit; and

a behavior of a device selected from a group consisting of at least one NMOS device of said integrated circuit and at least one PMOS device of said integrated circuit.

19. The system of claim 7 wherein said first circuit component comprises a ring oscillator operable for measuring leakage current.

13. A system comprising:

means for accessing a predetermined value of an operating characteristic of said integrated circuit, wherein said predetermined value correlates to a target value for an operating frequency of said integrated circuit;

means for measuring a current value of said operating characteristic; and

means for providing a level of voltage to said integrated circuit to cause said current value of said operating characteristic to approach said predetermined value and to cause said operating frequency to approach said target value.

14. The system of claim 13 further comprising:

means for operating said integrated circuit at said target value for said operating frequency.

15. The system of claim 13, wherein said means for providing a level of voltage is selected from a group consisting of:

a variable voltage supply operable to provide an operating voltage to said integrated circuit; and

a variable voltage supply operable to provide a body biasing voltage to said integrated circuit.

16. The system of claim 13, wherein said predetermined value comprises a frequency specific predetermined dynamic operating indicator value, and wherein said means for accessing further comprises means for accessing said predetermined value from a computer usable media.

17. The system of claim 13, wherein said means for accessing further comprises means for accessing said predetermined value from a data structure comprising a plurality of predetermined values, and wherein each of said plurality of predetermined values is associated with a respective operating frequency.

18. The system of claim 13, wherein said operating characteristic comprises at least one characteristic selected from a group consisting of:

a temperature of said integrated circuit;

a gate delay of said integrated circuit;

an off current of said integrated circuit;

a gate leakage of said integrated circuit; and

a behavior of a device selected from a group consisting of at least one NMOS device of said integrated circuit and at least one PMOS device of said integrated circuit.