Method and apparatus for real-time CPU thermal management and power conservation by adjusting CPU clock frequency in accordance with CPU activity

• US 5,996,084 A
• Filed: 01/17/1997
• Issued: 11/30/1999
• Est. Priority Date: 01/17/1996
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Watts, Vaughn
• Primary Examiner(s): Auve, Glenn A.
• Assistant Examiner(s): DHARIA, RUPAL
• Application Number:
  US08/785,619
• Time in Patent Office: 1,047 Days
• Field of Search: 395/750.01-750.08, 395/551-560, 713/300-340, 713/400-601
• US Class Current: 713/323
• CPC Class Codes: G06F 1/08 Clock generators with changeable or programmable clock frequency
• CPC Class Codes: G06F 1/206 comprising thermal management
• 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 11/3024 where the computing system component is a central processing unit [CPU]
• CPC Class Codes: G06F 11/3058 Monitoring arrangements for monitoring environmental properties or parameters of the computing system or of the computing system component, e.g. monitoring of power, currents, temperature, humidity, position, vibrations thermal management in cooling arrangements of a computing system G06F1/206
• CPC Class Codes: G06F 11/3423 where the assessed time is active or idle time
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A method and system (130) for controlling sensed CPU dynamic operating characteristics, such as CPU temperature, temperature change and power consumption, including the steps of and circuitry for sensing at least one dynamic CPU operating characteristic (140) while the CPU operates at a first clock rate (134). The system (130) determines that a setpoint interrupt condition exists (140), such as a temperature threshold, by virtue of the at least one sensed CPU dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint (140) that associates with the at least one dynamic operating characteristic. In the event that the setpoint interrupt condition exists, the circuitry and instructions control (144) the clock rate relative to the first clock rate. In the event that the setpoint interrupt condition does not exist, the circuitry and instructions repeat the above steps of determining the interrupt condition and controlling the clock rate. The method and system (130) also determine whether the CPU is in a compute-bound state (142). This operation in conjunction with a real-time power conservation apparatus and method (20) is a particularly attractive feature of the present invention.

Claims

1. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) in the event that said setpoint interrupt condition exists, modifying said first clock rate;

(d) in the event that said setpoint interrupt condition does not exist, determining whether said CPU is in a compute-bound state and, if said CPU is in a commute-bound state, further determining whether said interrupt condition will exist during said compute-bound state.

2. The method of claim 1, wherein said method for controlling sensed CPU dynamic operating characteristics comprises a method for managing the CPU dynamic thermal characteristics and further, wherein said step for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said determining step comprises the step of determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

3. The method of claim 1, wherein said step for sensing said at least one dynamic operating characteristic further comprises the step of sensing the operating temperature of said CPU, and further wherein said determining step comprises the step of determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

4. The method of claim 1, further comprising the steps of determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, controlling said clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

5. The method of claim 1, where said step for sensing said at least one CPU dynamic operating characteristic of said CPU comprises the step of sensing the operating temperature of said CPU using a thermistor sensing device.

6. The method of claim 1, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

7. The method of claim 1, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer, said memory location comprising a register.

8. The method of claim 1, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location associated with said computer, said memory location comprising a circuit other than said CPU.

9. The method of claim 2, further comprising a method for coordinated real-time power conservation and controlling sensed dynamic thermal characteristics in said CPU, said real-time power conservation method operating in association with said method of controlling said sensed CPU dynamic thermal characteristics and comprising the steps of:

determining whether said CPU is available for power conservation;

if said CPU is available for power conservation, determining a current clock rate for said CPU;

indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU;

determining whether a power conservation interrupt has occurred;

if said power conservation interrupt has not occurred, repeating this step wherein said CPU remains in said power conservation mode until said power conservation interrupt has occurred; and

if said power conservation interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU.

10. The method for coordinated real-time power conservation controlling sensed CPU dynamic thermal characteristics of claim 9, wherein said step of indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU, further comprises the steps of:

pulsing said hardware selector with a power conservation CPU command via a communication line to said hardware selector;

selecting a power conservation clock by said hardware selector based on said power conservation CPU command; and

passing pulses from said power conservation clock to said CPU to thereby place said CPU in a power conservation mode.

11. The method for coordinated real-time power conservation and controlling sensed CPU dynamic thermal characteristics of claim 9, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU is already in said power conservation mode;

if said CPU is not already in said power conservation mode, determining whether there are power conservation interrupts available to wake said CPU before said CPU is in said power conservation mode; and

if power conservation interrupts are available, preventing said CPU from entering said power conservation mode.

12. The method for real-time power conservation of claim 9, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU has received a request;

if said CPU has received a request, determining whether said request is a critical input/output;

preventing said CPU from entering said power conservation mode if said request is a critical input/output;

if said request is not a critical input/output, determining whether there are any power conservation interrupts available to wake said CPU before said CPU enters said power conservation mode;

preventing said CPU from entering said power conservation mode;

determining whether said request is from an input/output having a delay until the I/O device become ready; and

prevent said CPU from entering said power conservation mode if said request is not from an input/output having a delay.

13. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) in the event that said setpoint interrupt condition exists, modifying said first clock rate;

(d) in the event that said setpoint interrupt condition does not exist, determining whether said CPU is in a compute-bound state;

(e) if said CPU is in a compute-bound state, determining whether said at least one dynamic operating characteristic will exist in said interrupt condition during said compute-bound state, and,

(f) in the event that said interrupt condition will exist during said compute-bound state, modifying said interrupt condition.

14. The method of claim 13, wherein said method for controlling sensed CPU dynamic operating characteristics comprises a method for managing the CPU dynamic thermal characteristics and further, wherein said step for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said determining step comprises the step of determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

15. The method of claim 13, wherein said step for sensing said at least one dynamic operating characteristic further comprises the step of sensing the operating temperature of said CPU, and further wherein said determining step comprises the step of determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

16. The method of claim 13, further comprising the steps of determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

17. The method of claim 13, where said step for sensing said at least one CPU dynamic operating characteristic of said CPU comprises the step of sensing the operating temperature of said CPU using a thermistor sensing device.

18. The method of claim 13, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

19. The method of claim 13, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer, said memory location comprising a register.

20. The method of claim 13, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location associated with said computer, said memory location comprising a circuit other than said CPU.

21. The method of claim 14, further comprising a method for coordinated real-time power conservation and controlling sensed dynamic thermal characteristics in said CPU, said real-time power conservation method operating in association with said method of controlling said sensed CPU dynamic thermal characteristics and comprising the steps of:

determining whether said CPU is available for power conservation;

if said CPU is available for power conservation, determining a current clock rate for said CPU;

indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU;

determining whether a power conservation interrupt has occurred;

if said power conservation interrupt has not occurred, repeating this step wherein said CPU remains in said power conservation mode until said power conservation interrupt has occurred; and

if said power conservation interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU.

22. The method for coordinated real-time power conservation controlling sensed CPU dynamic thermal characteristics of claim 21, wherein said step of indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU, further comprises the steps of:

pulsing said hardware selector with a power conservation CPU command via a communication line to said hardware selector;

selecting a power conservation clock by said hardware selector based on said power conservation CPU command; and

passing pulses from said power conservation clock to said CPU to thereby place said CPU in a power conservation mode.

23. The method for coordinated real-time power conservation and controlling sensed CPU dynamic thermal characteristics of claim 21, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU is already in said power conservation mode;

if said CPU is not already in said power conservation mode, determining whether there are power conservation interrupts available to wake said CPU before said CPU is in said power conservation mode; and

if power conservation interrupts are available, preventing said CPU from entering said power conservation mode.

24. The method for real-time power conservation of claim 21, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU has received a request;

if said CPU has received a request, determining whether said request is a critical input/output;

preventing said CPU from entering said power conservation mode if said request is a critical input/output;

if said request is not a critical input/output, determining whether there are any power conservation interrupts available to wake said CPU before said CPU enters said power conservation mode;

preventing said CPU from entering said power conservation mode;

determining whether said request is from an input/output having a delay until the I/O device become ready; and

prevent said CPU from entering said power conservation mode if said request is not from an input/output having a delay.

25. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) in the event that said setpoint interrupt condition exists, modifying said first clock rate;

(d) in the event that said setpoint interrupt condition does not exist, determining whether said CPU is in a compute-bound state; and

(e) if said CPU is in a compute-bound state, determining the duration of said compute-bound state by determining the amount of compute-bound instructions that said CPU is to execute during said compute-bound state.

26. The method of claim 25, wherein said method for controlling sensed CPU dynamic operating characteristics comprises a method for managing the CPU dynamic thermal characteristics and further, wherein said step for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said determining step comprises the step of determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

27. The method of claim 25, wherein said step for sensing said at least one dynamic operating characteristic further comprises the step of sensing the operating temperature of said CPU, and further wherein said determining step comprises the step of determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

28. The method of claim 25, further comprising the steps of determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

29. The method of claim 25, where said step for sensing said at least one CPU dynamic operating characteristic of said CPU comprises the step of sensing the operating temperature of said CPU using a thermistor sensing device.

30. The method of claim 25, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

31. The method of claim 25, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer, said memory location comprising a register.

32. The method of claim 25, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location associated with said computer, said memory location comprising a circuit other than said CPU.

33. The method of claim 26, further comprising a method for coordinated real-time power conservation and controlling sensed dynamic thermal characteristics in said CPU, said real-time power conservation method operating in association with said method of controlling said sensed CPU dynamic thermal characteristics and comprising the steps of:

determining whether said CPU is available for power conservation;

if said CPU is available for power conservation, determining a current clock rate for said CPU;

indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU;

determining whether a power conservation interrupt has occurred;

if said power conservation interrupt has not occurred, repeating this step wherein said CPU remains in said power conservation mode until said power conservation interrupt has occurred; and

if said power conservation interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU.

34. The method for coordinated real-time power conservation controlling sensed CPU dynamic thermal characteristics of claim 33, wherein said step of indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU, further comprises the steps of:

pulsing said hardware selector with a power conservation CPU command via a communication line to said hardware selector;

selecting a power conservation clock by said hardware selector based on said power conservation CPU command; and

passing pulses from said power conservation clock to said CPU to thereby place said CPU in a power conservation mode.

35. The method for coordinated real-time power conservation and controlling sensed CPU dynamic thermal characteristics of claim 33, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU is already in said power conservation mode;

if said CPU is not already in said power conservation mode, determining whether there are power conservation interrupts available to wake said CPU before said CPU is in said power conservation mode; and

if power conservation interrupts are available, preventing said CPU from entering said power conservation mode.

36. The method for real-time power conservation of claim 33, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU has received a request;

if said CPU has received a request, determining whether said request is a critical input/output;

preventing said CPU from entering said power conservation mode if said request is a critical input/output;

if said request is not a critical input/output, determining whether there are any power conservation interrupts available to wake said CPU before said CPU enters said power conservation mode;

preventing said CPU from entering said power conservation mode;

determining whether said request is from an input/output having a delay until the I/O device become ready; and

prevent said CPU from entering said power conservation mode if said request is not from an input/output having a delay.

37. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) in the event that said setpoint interrupt condition exists, modifying said first clock rate;

(d) in the event that said setpoint interrupt condition does not exist, determining whether said CPU is in a compute-bound state and, if said CPU is in a compute-bound state, determining the duration of said compute-bound state by determining the amount of compute-bound instructions that said CPU is to execute during said compute-bound state; and

(e) modifying said interrupt condition in the event that said interrupt condition will exist during said compute-bound state.

38. The method of claim 37, wherein said method for controlling sensed CPU dynamic operating characteristics comprises a method for managing the CPU dynamic thermal characteristics and further, wherein said step for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said determining step comprises the step of determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

39. The method of claim 37, wherein said step for sensing said at least one dynamic operating characteristic further comprises the step of sensing the operating temperature of said CPU, and further wherein said determining step comprises the step of determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

40. The method of claim 37, further comprising the steps of determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

41. The method of claim 37, where said step for sensing said at least one CPU dynamic operating characteristic of said CPU comprises the step of sensing the operating temperature of said CPU using a thermistor sensing device.

42. The method of claim 37, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

43. The method of claim 37, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer, said memory location comprising a register.

44. The method of claim 37, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location associated with said computer, said memory location comprising a circuit other than said CPU.

45. The method of claim 38, further comprising a method for coordinated real-time power conservation and controlling sensed dynamic thermal characteristics in said CPU, said real-time power conservation method operating in association with said method of controlling said sensed CPU dynamic thermal characteristics and comprising the steps of:

determining whether said CPU is available for power conservation;

if said CPU is available for power conservation, determining a current clock rate for said CPU;

indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU;

determining whether a power conservation interrupt has occurred;

if said power conservation interrupt has not occurred, repeating this step wherein said CPU remains in said power conservation mode until said power conservation interrupt has occurred; and

if said power conservation interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU.

46. The method for coordinated real-time power conservation controlling sensed CPU dynamic thermal characteristics of claim 45, wherein said step of indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU, further comprises the steps of:

pulsing said hardware selector with a power conservation CPU command via a communication line to said hardware selector;

selecting a power conservation clock by said hardware selector based on said power conservation CPU command; and

passing pulses from said power conservation clock to said CPU to thereby place said CPU in a power conservation mode.

47. The method for coordinated real-time power conservation and controlling sensed CPU dynamic thermal characteristics of claim 45, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU is already in said power conservation mode;

if said CPU is not already in said power conservation mode, determining whether there are power conservation interrupts available to wake said CPU before said CPU is in said power conservation mode; and

if power conservation interrupts are available, preventing said CPU from entering said power conservation mode.

48. The method for real-time power conservation of claim 45, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU has received a request;

if said CPU has received a request, determining whether said request is a critical input/output;

preventing said CPU from entering said power conservation mode if said request is a critical input/output;

if said request is not a critical input/output, determining whether there are any power conservation interrupts available to wake said CPU before said CPU enters said power conservation mode;

preventing said CPU from entering said power conservation mode;

determining whether said request is from an input/output having a delay until the I/O device become ready; and

prevent said CPU from entering said power conservation mode if said request is not from an input/output having a delay.

49. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) in the event that said setpoint interrupt condition exists, modifying said first clock rate;

(d) in the event that said setpoint interrupt condition does not exist, determining whether said CPU is in a compute-bound state;

(e) if said CPU is in a compute-bound state, determining the duration of said compute-bound state; and

(f) further modify said first clock rate to avoid the existence of said interrupt condition during said compute-bound state.

50. The method of claim 49, wherein said method for controlling sensed CPU dynamic operating characteristics comprises a method for managing the CPU dynamic thermal characteristics and further, wherein said step for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said determining step comprises the step of determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

51. The method of claim 49, wherein said step for sensing said at least one dynamic operating characteristic further comprises the step of sensing the operating temperature of said CPU, and further wherein said determining step comprises the step of determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

52. The method of claim 49, further comprising the steps of determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

53. The method of claim 49, where said step for sensing said at least one CPU dynamic operating characteristic of said CPU comprises the step of sensing the operating temperature of said CPU using a thermistor sensing device.

54. The method of claim 49, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

55. The method of claim 49, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location of said computer, said memory location comprising a register.

56. The method of claim 49, further comprising the step of storing said predetermined relationship and said predetermined setpoint in a memory location associated with said computer, said memory location comprising a circuit other than said CPU.

57. The method of claim 50, further comprising a method for coordinated real-time power conservation and controlling sensed dynamic thermal characteristics in said CPU, said real-time power conservation method operating in association with said method of controlling said sensed CPU dynamic thermal characteristics and comprising the steps of:

determining whether said CPU is available for power conservation;

if said CPU is available for power conservation, determining a current clock rate for said CPU;

indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU;

determining whether a power conservation interrupt has occurred;

if said power conservation interrupt has not occurred, repeating this step wherein said CPU remains in said power conservation mode until said power conservation interrupt has occurred; and

if said power conservation interrupt has occurred, indicating to said hardware selector to restore said determined current clock rate to said CPU.

58. The method for coordinated real-time power conservation controlling sensed CPU dynamic thermal characteristics of claim 57, wherein said step of indicating to a hardware selector to reduce or stop the current clock rate provided to the CPU, further comprises the steps of:

pulsing said hardware selector with a power conservation CPU command via a communication line to said hardware selector;

selecting a power conservation clock by said hardware selector based on said power conservation CPU command; and

passing pulses from said power conservation clock to said CPU to thereby place said CPU in a power conservation mode.

59. The method for coordinated real-time power conservation and controlling sensed CPU dynamic thermal characteristics of claim 57, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU is already in said power conservation mode;

if said CPU is not already in said power conservation mode, determining whether there are power conservation interrupts available to wake said CPU before said CPU is in said power conservation mode; and

if power conservation interrupts are available, preventing said CPU from entering said power conservation mode.

60. The method for real-time power conservation of claim 57, wherein said step of determining whether a central processing unit (CPU) in a computer is available for power conservation, further comprises the steps of:

checking to see if said CPU has received a request;

if said CPU has received a request, determining whether said request is a critical input/output;

preventing said CPU from entering said power conservation mode if said request is a critical input/output;

if said request is not a critical input/output, determining whether there are any power conservation interrupts available to wake said CPU before said CPU enters said power conservation mode;

preventing said CPU from entering said power conservation mode;

determining whether said request is from an input/output having a delay until the I/O device become ready; and

prevent said CPU from entering said power conservation mode if said request is not from an input/output having a delay.

61. An apparatus for controlling sensed CPU dynamic operating characteristics, comprising:

(a) sensing circuitry for sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) setpoint instructions for operating on said CPU for determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) control instructions for modifying said first clock rate in the event that said setpoint interrupt condition exists; and

(d) compute-bound determining instructions for determining whether said CPU is in a compute-bound state and, if said CPU is in a compute-bound state, further determining whether said interrupt condition will exist during said compute-bound state.

62. The apparatus of claim 61, further comprising managing instructions for managing the CPU dynamic thermal characteristics, and wherein said temperature sensing circuitry further comprises dynamic temperature sensing circuitry for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said setpoint instructions further comprise instructions for determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

63. The apparatus of claim 61, wherein said sensing circuitry further comprises circuitry for sensing the operating temperature of said CPU, and further wherein said setpoint instructions further comprise instructions for determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

64. The apparatus of claim 61, further comprising power conservation instructions for determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

65. The apparatus of claim 61, where said sensing circuitry comprises a thermistor sensing device.

66. The apparatus of claim 61, further comprising memory circuitry for storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

67. An apparatus for controlling sensed CPU dynamic operating characteristics, comprising:

(a) sensing circuitry for sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) setpoint instructions for operating on said CPU for determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) control instructions for modifying said first clock rate in the event that said setpoint interrupt condition exists; and

(d) compute-bound determining instructions for determining whether said CPU is in a compute-bound state wherein said setpoint instructions further comprising instructions for determining whether said at least one dynamic operating characteristic will exist in said interrupt condition during said compute-bound state, and further comprising modifying instructions for modifying said interrupt condition in the event that said interrupt condition will exist during said compute-bound state.

68. The apparatus of claim 67, further comprising managing instructions for managing the CPU dynamic thermal characteristics, and wherein said temperature sensing circuitry further comprises dynamic temperature sensing circuitry for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said setpoint instructions further comprise instructions for determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

69. The apparatus of claim 67, wherein said sensing circuitry further comprises circuitry for sensing the operating temperature of said CPU, and further wherein said setpoint instructions further comprise instructions for determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

70. The apparatus of claim 67, further comprising power conservation instructions for determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

71. The apparatus of claim 67, where said sensing circuitry comprises a thermistor sensing device.

72. The apparatus of claim 67, further comprising memory circuitry for storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

73. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing circuitry for sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) setpoint instructions for operating on said CPU for determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) control instructions for modifying said first clock rate in the event that said setpoint interrupt condition exists; and

(d) compute-bound determining instructions for determining whether said CPU is in a compute-bound state and, if said CPU is in a compute-bound state, determining the duration of said compute-bound state by determining the amount of compute-bound instructions that said CPU is to execute during said compute-bound state.

74. The apparatus of claim 73, further comprising managing instructions for managing the CPU dynamic thermal characteristics, and wherein said temperature sensing circuitry further comprises dynamic temperature sensing circuitry for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said setpoint instructions further comprise instructions for determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

75. The apparatus of claim 73, wherein said sensing circuitry further comprises circuitry for sensing the operating temperature of said CPU, and further wherein said setpoint instructions further comprise instructions for determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

76. The apparatus of claim 73, further comprising power conservation instructions for determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

77. The apparatus of claim 73, where said sensing circuitry comprises a thermistor sensing device.

78. The apparatus of claim 73, further comprising memory circuitry for storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

79. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing circuitry for sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) setpoint instructions for operating on said CPU for determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) control instructions for modifying said first clock rate in the event that said setpoint interrupt condition exists; and

(d) compute-bound determining instructions for determining whether said CPU is in a compute-bound state and determining the duration of said compute-bound state by determining the amount of compute-bound instructions that said CPU is to execute during said compute-bound state, and, further, modifying said interrupt condition in the event that said interrupt condition will exist during said compute-bound state.

80. The apparatus of claim 79, further comprising managing instructions for managing the CPU dynamic thermal characteristics, and wherein said temperature sensing circuitry further comprises dynamic temperature sensing circuitry for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said setpoint instructions further comprise instructions for determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

81. The apparatus of claim 79, wherein said sensing circuitry further comprises circuitry for sensing the operating temperature of said CPU, and further wherein said setpoint instructions further comprise instructions for determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

82. The apparatus of claim 79, further comprising power conservation instructions for determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

83. The apparatus of claim 79, where said sensing circuitry comprises a thermistor sensing device.

84. The apparatus of claim 79, further comprising memory circuitry for storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.

85. A method for controlling sensed CPU dynamic operating characteristics, comprising the steps of:

(a) sensing circuitry for sensing at least one dynamic operating characteristic of a central processing unit (CPU) in a computer, said CPU operating at a first clock rate;

(b) setpoint instructions for operating on said CPU for determining that a setpoint interrupt condition exists by virtue of said at least one dynamic operating characteristic establishing a predetermined relationship relative to a predetermined setpoint associated with said at least one dynamic operating characteristic;

(c) control instructions for modifying said first clock rate in the event that said setpoint interrupt condition exists; and

(d) compute-bound determining instructions for determining whether said CPU is in a compute-bound state and, if said CPU is in a compute-bound state, determining the duration of said compute-bound state and further modify said first clock rate for avoiding the existence of said interrupt condition during said compute-bound state.

86. The apparatus of claim 85, further comprising managing instructions for managing the CPU dynamic thermal characteristics, and wherein said temperature sensing circuitry further comprises dynamic temperature sensing circuitry for sensing said at least one dynamic operating characteristic comprises the step of sensing the operating temperature of said CPU and further, wherein said setpoint instructions further comprise instructions for determining the existence of an interrupt condition wherein said operating temperature establishes a predetermined relationship relative to a predetermined temperature setpoint.

87. The apparatus of claim 85, wherein said sensing circuitry further comprises circuitry for sensing the operating temperature of said CPU, and further wherein said setpoint instructions further comprise instructions for determining that said operating temperature approaches a predetermined temperature setpoint during a period in which said CPU is in a compute-bound state.

88. The apparatus of claim 85, further comprising power conservation instructions for determining whether said CPU is available for power conservation and, if said CPU is available for power conservation, modifying said first clock rate relative to a saved clock rate according to the existence of said interrupt condition and control signals arising from said power conservation.

89. The apparatus of claim 85, where said sensing circuitry comprises a thermistor sensing device.

90. The apparatus of claim 85, further comprising memory circuitry for storing said predetermined relationship and said predetermined setpoint in a memory location of said computer.