Prevention of power state change in response to chassis intrusion when computer system is not in powered up power state

• US 6,795,926 B1
• Filed: 05/28/1999
• Issued: 09/21/2004
• Est. Priority Date: 05/28/1999
• Status: Expired due to Term

• Current Assignee: Dell USA LP (Dell Technologies Inc.)
• Original Assignee: Dell USA LP (Dell Technologies Inc.)
• Inventors: Matula, Terry L., Stuewe, John R.
• Primary Examiner(s): Browne, Lynne H.
• Assistant Examiner(s): CHEN, TSE W
• Application Number:
  US09/322,296
• Time in Patent Office: 1,943 Days
• Field of Search: 713/300, 713/310
• US Class Current: 713/300
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode

Abstract

A gating circuit for a computer system to prevent a power management signal provided by a computer card slot connector or a system board mounted device to change the power state of the computer system from a lower power state to a higher power state when the chassis of the computer system is open. The computer system includes a chassis intrusion detection switch to provide an indication of whether the chassis is open. In one example, the computer card connector is a card slot connector that conforms to the PCI or AGP computer bus standards, and the power management signal is a PME# signal. The gating circuit also prevents a wake on LAN (WOL) signal received via a jumper from a WOL circuit from changing the power state of the computer system from a lower power state to a higher power state. When the gating circuit receives an indication that the computer system is in a powered up power state, the gating circuit provides a gated power signal to change the power state of the computer system in response to receiving a PME# or WOL signal regardless of whether the chassis is open or closed. The computer system implements a power management strategy such as the Advanced Configuration and Power Interface power strategy. The gating circuit prevents a PME# signal or WOL signal from placing a computer circuit in a higher power state from a non powered up power state during the installation of a computer card in the computer system.

Claims

1. A computer system comprising:

at least one connector, each connector configured to be coupled to a respective computer card circuit to provide a power management signal from the computer card circuit indicating a request to change a power state of the computer system;

a chassis detection circuit having an output to provide an indication signal of whether a chassis of the computer system is open or closed;

a gating circuit operably coupled to the chassis detection circuit to receive the indication signal from the chassis detection circuit and operably coupled to the at least one connector, the gating circuit having an output to selectively provide, as determined by the indication signal, a gated power management signal to initiate the placement of the computer system in a higher power state from a lower power state in response to receiving a power management signal from the at least one connector, wherein the gating circuit provides a gated power management signal when the indication signal indicates that the chassis is closed, wherein the gating circuit does not provide the gated power management signal when the indication signal indicates that the chassis is open;

the gating circuit including an input to receive a power state indication signal indicating that the computer system is in a powered up power state; and

when the indication signal indicates that the computer system is in a powered up state, the gating circuit providing at its output a signal to initiate a change in the power state of the computer system in response to receiving a power management signal from the at least one connector regardless of whether the indication signal of the chassis detection circuit indicates whether the chassis is open or closed.

2. The computer system of claim 1 wherein the at least one connector includes:

at least one card slot connector operably coupled to a computer bus of the computer system, each card slot connector capable of receiving a respective computer card, each of the at least one card slot connector capable of providing a power management signal from a computer card circuit of the respective computer card.

3. The computer system of claim 2 wherein a first group of the at least one card slot connector substantially conform to a peripheral component interface (PCI) standard.

4. The computer system of claim 1 wherein:

the at least one connector includes a plurality of connectors;

each connector of the plurality includes a terminal for providing the power management signal from a respective computer card circuit; and

each of the terminals for providing the power management signal are electrically coupled together in a wired-ORed configuration and are electrically coupled to an input of the gating circuit.

5. The computer system of claim 1 further comprising:

a controller circuit capable of initiating the placement of the computer system in a higher power state in response to receiving the gated power management signal from the gating circuit.

6. The computer system of claim 1 wherein the power management signal includes a Power Management Event (PME#) signal.

7. The computer system of claim 1 wherein the lower power state is a non powered up power state.

8. The computer system of claim 1 wherein the chassis detection circuit includes a chassis intrusion switch located on a frame member of the chassis, the chassis further including an outer cover having at least one outer panel, the intrusion switch being at a first switch state indicating that the chassis is closed when the cover is properly positioned on the frame member of the chassis, the intrusion switch being at a second switch state indicating that the chassis is open when the cover is removed from the frame member.

9. The computer system of claim 1 wherein the at least one connector is coupled to a computer card circuit of a computer card via a jumper and receives a power management signal from the computer card circuit via the jumper.

10. The computer system of claim 1 further comprising:

a computer card circuit coupled to one of the at least one connectors, the computer card circuit including circuitry to receive a wake on LAN (WOL) signal from a remote device and provide a power management signal in response to the receipt of the WOL signal.

11. The computer system of claim 1 wherein one of the connectors is coupled to a computer card circuit configured to receive signals from a remote device, the computer card circuit generates a power management signal in response to receiving from the remote device a signal to change the power state of the computer system.

12. The computer system of claim 1 wherein the lower power state is a soft off power state.

13. The computer system of claim 1 wherein the computer system implements a power management strategy based upon an Advanced Configuration and Power Interface (ACPI) standard.

14. The computer system of claim 1 wherein the higher power state is an on power state.

15. The computer system of claim 14 wherein the on power state is a working power state.

16. The computer system of claim 1 further comprising:

a computer device mounted on a system board of the computer system, the computer device coupled to the gating circuit to provide a power management signal to request a change in the power state of the computer system, wherein the gating circuit selectively provides, as determined by the indication signal, a gated power management signal to initiate the placement of the computer system in a higher power state from a lower power state in response to receiving a power management signal from the computer device, wherein the gating circuit provides the gated power management signal when the indication signal indicates that the chassis is closed, wherein the gating circuit does not provide the gated power management signal when the indication signal indicates that the chassis is open.

17. A method for controlling a change in a power state of a computer system, the method comprising:

receiving a request signal from a computer card circuit connector to change the power state of a computer system;

determining whether the chassis is open or closed;

preventing the request signal from placing the computer system in a higher power state from a lower power state if the chassis is determined to be open; and

changing the power state of the computer system in response to receiving the request signal to change the power state of the computer system when the computer system is in a powered up power state regardless of the determination of whether the chassis is open or closed.

18. The method of claim 17 further comprising:

placing the computer system in a higher power state from a lower state in response to the request signal if the chassis is determined to be closed.

19. The method of claim 17 further comprising:

receiving by a computer card circuit operably connected to the computer card circuit connector a request from a remote device to change the power state of the computer system; and

providing by the computer card circuit via the computer card circuit connector a request signal to change the power state of the computer system in response to receiving the request from the remote device.

20. The method of claim 17 wherein:

the lower power state is a non powered up power state.

21. The method of claim 17 wherein the request signal includes a PME# signal.

22. A computer system comprising:

a chassis detection circuit having an output to provide an indication signal of whether a chassis of the computer system is open or closed;

means for preventing a power management signal provided by a computer card circuit connector from changing a power state of the computer system to a higher power state from a lower power state when the indication signal indicates that the chassis is open;

the means for preventing including an input to receive a power state indication signal indicating that the computer system is in a powered up power state; and

when the indication signal indicates that the computer system is in a powered up power state, the means for preventing providing at an output a signal to initiate a change in the power state of the computer system in response to receiving a power management signal from a computer card connector circuit regardless of whether the indication signal of the chassis detection circuit indicates whether the chassis is open or closed.

23. The computer system of claim 22 wherein the computer card circuit connector is connected to a computer card circuit via a jumper.

24. The computer system of claim 22 further comprising:

at least one computer card slot connector, each computer card slot connector coupled to a computer bus and capable of receiving a respective computer card, each computer card slot connector operably coupled to the means for preventing to provide to the means for preventing a power management signal generated by a respective computer card circuit located on a respective computer card.

25. The computer system of claim 24 wherein the lower power state is a soft off power state.

26. The computer system of claim 22 wherein the power management signal includes a Power Management Even (PME#) signal.

27. The computer system of claim 22 wherein the chassis detection circuit includes a chassis intrusion switch located on a frame member of the chassis, the chassis further including an outer cover having at least one outer panel, the intrusion switch being at a first switch state indicating that the chassis is closed when the cover is properly positioned on the frame member of the chassis, the intrusion switch being at a second switch state indicating that the chassis is open when the cover is removed from the frame member.

28. The computer system of claim 22 wherein the higher power state is an on power state.

29. The computer system of claim 22 wherein the lower power state is a non powered up power state.

30. A computer system comprising:

at least one computer bus;

a plurality of computer devices, each computer device is operably coupled to one of the at least one computer bus, each computer device has an output to provide a power management signal to change a power state of the computer system;

a chassis detection circuit having an output to provide an indication signal of whether a chassis of the computer system is open or closed;

a gating circuit coupled to the outputs of the plurality of computer devices to receive the power management signals and coupled to the chassis detection circuit to receive the indication signal, the gating circuit having an output to provide a gated power management signal to initiate a change in the power state of the computer system in response to receiving a power management signal from one of the computer devices, wherein the gating circuit does not provide the gated power management signal to change the power state of the computer system to a higher power state from a lower power state when the indication signal indicates that the chassis is open;

the gating circuit including an input to receive a power state indication signal indicating that the computer system is in a powered up power state; and

when the indication signal indicates that the computer system is in a powered up state, the gating circuit providing the sated power signal to change the power state of the computer system in response to receiving a power management signal regardless of whether the indication signal of the chassis detection circuit indicates whether the chassis is open or closed.

31. The computer system of claim 30 wherein at least one of the at least one computer bus substantially conforms to a Peripheral Component Interface (PCI) standard.

32. The computer system of claim 30 wherein:

each of the outputs for providing the power management signal are electrically coupled together in a wired-ORed configuration and are electrically coupled to an input of the gating circuit.

34. The computer system of claim 30 further wherein:

one computer device of the plurality of computer devices is configured to receive a remote request to change the power state of the computer system, the one computer device generates a power management signal in response to receiving the remote request.

35. The computer system of claim 30 wherein the lower power state is a non powered up power state.

36. The computer system of claims 30 wherein the computer system implements a power management strategy based upon an Advanced Configuration and Power Interface (ACPI) standard, wherein an S1 sleeping power state is a powered up power state.

37. The computer system of claim 30 wherein:

each of a first group of the plurality of computer devices is mounted on a computer card inserted into a slot connector connected to one of the computer busses.

38. The computer system of claim 30 wherein the computer system implements a power management strategy based upon an Advanced Configuration and Power Interface (ACPI) standard.

33. The computer system of claim 33 wherein the power management signal provided by the computer devices includes a Power Management Even (PME#) signal.

39. A computer system comprising:

a chassis detection circuit having an output to provide an indication signal of whether a chassis of the computer system is open or closed;

a gating circuit operably coupled to the chassis detection circuit to receive the indication signal from the chassis detection circuit, the gating circuit having at least one input to receive a PME# signal, the gating circuit having an output to selectively provide, as determined by the indication signal, a gated power management signal to initiate the placement of the computer system in a higher power state from a lower power state in response to receiving a PME# signal, wherein the gating circuit provides the gated power management signal when the indication signal indicates that the chassis is closed, wherein the gating circuit does not provide the gated power management signal when the indication signal indicates that the chassis is open;

the gating circuit including an input to receive a power state indication signal indicating that the computer system is in a powered up power state; and

when the indication signal indicates that the computer system is in a powered up power state, the gating circuit providing at its output a signal to initiate a change in the power state of the computer system in response to receiving a PME# signal regardless of whether the indication signal of the chassis detection circuit indicates whether the chassis is open or closed.

40. The computer system of claim 39 further comprising:

at least one connector, each connector including a PME# terminal electrically coupled to one of the at least one input of the gating circuit, each connector is configured to be coupled to a respective computer card circuit to provide a PME# signal from the computer card circuit via the PME# terminal; and

at least one device mounted on a system board of the computer system, each device having a PME# terminal electrically coupled to one of the at least one input of the gating circuit for providing a PME# signal generated by the at least one device.

41. A computer system comprising:

means for receiving a request signal from a computer card circuit connector to change the power state of a computer system;

means for determining whether a chassis of the computer system is open or closed;

means for preventing the request signal from placing the computer system in a higher power state from a lower power state if the chassis is determined to be open; and

means for changing the power state of the computer system in response to receiving the request signal to change the power state of the computer system when the computer system is in a powered up power state regardless of the determination of whether the chassis is open or closed.