Computer system thermal management

• US 6,112,164 A
• Filed: 03/31/1998
• Issued: 08/29/2000
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Hobson, Louis B.
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US09/052,438
• Time in Patent Office: 882 Days
• Field of Search: 702/132, 713/320, 713/300, 713/322, 713/323, 713/324, 713/330, 327/512, 327/513
• US Class Current: 702/132
• CPC Class Codes: G06F 1/206 comprising thermal management

Abstract

A thermal management technique for a computer system having a thermal device and a timer includes establishing a thermal window having low and high temperature thresholds, causing the timer to generate an interrupt at a specified interval, and processing the interrupt. During interrupt processing, if the thermal device indicates the current temperature is outside the established thermal window, the thermal window is adjusted by resetting the low and high temperature thresholds to bracket the current temperature and then notifying the operating system that a thermal event has occurred.

Claims

1. A thermal management method for a computer system having a thermal device and a timer, the method comprising:

establishing a thermal window;

causing the timer to generate an interrupt at a specified interval;

processing the interrupt by determining if a current temperature is outside the established thermal window and, if so, notifying an operating system.

2. The method of claim 1, wherein the thermal device comprises a National Semiconductor LM75 device.

3. The method of claim 1, wherein establishing a thermal window comprises:

determining a current temperature of the computer system;

setting a low temperature threshold to a value corresponding to the current temperature minus a specified temperature difference; and

setting a high temperature threshold to a value corresponding to the current temperature plus the specified temperature difference.

4. The method of claim 1, wherein the specified temperature difference is between approximately 1 degree Centigrade and approximately 15 degrees Centigrade.

5. The method of claim 4, wherein the specified temperature difference is approximately 5 degrees Centigrade.

6. The method of claim 1, wherein the specified interval is between approximately 1 second and approximately 300 seconds.

7. The method of claim 6, wherein the specified interval is approximately 10 seconds.

8. The method of claim 1, wherein the interrupt is an advanced configuration and power interface transparent interrupt.

9. The method of claim 8, wherein the advanced configuration and power interface transparent interrupt is a system management interrupt.

10. The method of claim 1 further comprising adjusting the thermal window if the current temperature is outside the established thermal window.

11. The method of claim 10, wherein adjusting the thermal window comprises:

resetting a low temperature threshold to a value corresponding to the current temperature minus a specified temperature difference; and

resetting a high temperature threshold to a value corresponding to the current temperature plus the specified temperature difference.

12. The method of claim 11, wherein the specified temperature difference is approximately 5 degrees Centigrade.

13. A thermal management method for a computer system executing an advanced configuration and power interface operating system having a thermal device and a timer, the method comprising:

determining an initial temperature of the computer system;

establishing a thermal window by setting a low temperature threshold to the initial temperature minus a specified temperature difference and setting a high temperature threshold to the initial temperature plus the specified temperature difference;

initializing the timer to generate a system management interrupt at a specified interval;

processing the interrupt by determining a current temperature of the computer system and, if the current temperature is outside the established thermal window, then

resetting the low temperature threshold to a value corresponding to the current temperature minus the specified temperature difference,

resetting the high temperature threshold to a value corresponding to the current temperature plus the specified temperature difference, and

notifying the operating system that a thermal event has occurred.

14. The method of claim 13, wherein the thermal device comprises a National Semiconductor LM75 device.

15. The method of claim 13, wherein the specified temperature difference is between approximately 1 degree Centigrade and approximately 15 degrees Centigrade.

16. The method of claim 15, wherein the specified temperature difference is approximately 5 degrees Centigrade.

17. The method of claim 13, wherein the specified interval is between approximately 1 second and approximately 300 seconds.

18. The method of claim 17, wherein the specified interval is approximately 10 seconds.

19. A computer system comprising:

a bus;

a host processor electrically coupled to the bus and adapted to execute an advanced configuration and power interface operating system;

an input-output device electrically coupled to the bus;

a thermal device electrically coupled to the bus and thermally coupled to a device of the computer system;

a timer electrically coupled to the bus and adapted to generate an interrupt at a specified interval; and

a thermal circuit operatively coupled to the thermal device and the timer and adapted to;

receive the interrupt,

obtain a temperature value from the thermal device, and

determine if the temperature value is outside a predefined thermal window and, if it is, adjust the predefined thermal window and notify the operating system by a system control interrupt.

20. The computer system of claim 19, wherein the thermal device is a National Semiconductor LM75 device.

21. The computer system of claim 19, wherein the input-output device is a network interface card.

22. The computer system of claim 19, wherein the thermal device is thermally coupled to the host processor.

23. The computer system of claim 19, wherein the specified interval is between approximately 1 second and approximately 300 seconds.

24. The computer system of claim 19, wherein the interrupt is a system management interrupt.

25. The computer system of claim 24, wherein the thermal circuit is a system management interrupt handler.

26. A computer program for thermal management of a computer system adapted to execute an advanced configuration and power interface operating system and having a thermal device, the computer program being stored on a media readable by the computer system and comprising instructions for causing the computer system to:

establish a thermal window;

cause a timer to generate an interrupt at a specified interval;

process the interrupt by obtaining a current temperature value from the thermal device and, if the current temperature is outside the established thermal window, notifying the operating system that a thermal event has occurred.

27. The computer program of claim 26, wherein the thermal device comprises a National Semiconductor LM75 device.

28. The computer program of claim 26, wherein the media is system read only memory.

29. The computer program of claim 26, wherein the instructions for establishing a thermal window comprise instructions to:

read a current temperature value from the thermal device;

set a low temperature threshold to a value corresponding to the current temperature minus a specified temperature difference; and

set a high temperature threshold to a value corresponding to the current temperature plus the specified temperature difference.

30. The computer program of claim 29, wherein the specified temperature difference is between approximately 1 degree Centigrade and approximately 15 degrees Centigrade.

31. The computer program of claim 30, wherein the specified temperature difference is approximately 5 degrees Centigrade.

32. The computer program of claim 26, wherein the specified interval is between approximately 1 second and approximately 300 seconds.

33. The computer program of claim 32, wherein the specified interval is approximately 10 seconds.

34. The computer program of claim 26, wherein the interrupt is transparent to the advanced configuration and power interface operating system.

35. The computer program of claim 34, wherein the transparent interrupt is a system management interrupt.

36. The computer program of claim 26 further comprising instructions to adjust the thermal window if the current temperature is outside the established thermal window.

37. The computer program of claim 36, wherein the instructions to adjust the established thermal window comprise instructions to:

reset a low temperature threshold to a value corresponding to the current temperature minus a specified temperature difference; and

reset a high temperature threshold to a value corresponding to the current temperature plus the specified temperature difference.

38. The computer program of claim 37, wherein the specified temperature difference is approximately 5 degrees Centigrade.

39. A method for use in thermal management in a computer system adapted to execute an operating system that includes a thermal device that senses a temperature in the computer system but does not initiate delivery of thermal information to the operating system except when the sensed temperature passes out of a programmable preset thermal window, the method comprising;

maintaining a thermal window having low temperature and high temperature threshold values; and

adjusting the thermal window in response to the sensed temperature if the sensed temperature is outside the thermal window.

40. The method of claim 39, wherein the thermal device comprises a National Semiconductor LM75 device.

41. The method of claim 39, wherein adjusting the thermal window comprises:

adjusting the low temperature threshold to a value corresponding to the sensed temperature minus a specified temperature difference; and

adjusting the high temperature threshold to a value corresponding to the sensed temperature plus the specified temperature difference.

42. The method of claim 41, wherein the specified temperature difference is between approximately 1 degree Centigrade and approximately 15 degrees Centigrade.

43. The method of claim 42, wherein the specified temperature difference is approximately 5 degrees Centigrade.

44. The method of claim 39, wherein the thermal device senses a temperature every n seconds.

45. The method of claim 44, wherein n is between approximately 1 second and approximately 300 seconds.

46. The method of claim 45, wherein n is approximately 10 seconds.

47. The method of claim 39, wherein the operating system is an advanced configuration and power interface operating system.