Peripheral device feature allowing processors to enter a low power state
DCFirst Claim
1. A system, comprising:
- a processor;
a host controller coupled to the processor; and
a device coupled to the host controller;
wherein the device is electrically disconnected from the host controller if the device is not in an active state; and
wherein the device being electrically disconnected from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and
wherein a sideband signal is used to signal the device to electrically reconnect after the device has been electrically disconnected.
6 Assignments
Litigations
2 Petitions
Accused Products
Abstract
If a USB device is turned off or is not active, the device may be electrically disconnected from a USB host controller. The device may be electrically disconnected through a physical interface on the device. In some embodiments, if the device becomes active during a wait period (e.g., 2–3 seconds) prior to electrically disconnecting the device, the device may not be electrically disconnected. In some embodiments, when the device is electrically disconnected from the USB host controller and no system activity of a bus mastering peripheral is occurring, the CPU may enter a low power state if other conditions are met. In some embodiments, if the USB device becomes active after electrically disconnecting, the electrical disconnection may be discontinued.
80 Citations
82 Claims
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1. A system, comprising:
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a processor; a host controller coupled to the processor; and a device coupled to the host controller; wherein the device is electrically disconnected from the host controller if the device is not in an active state; and wherein the device being electrically disconnected from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and wherein a sideband signal is used to signal the device to electrically reconnect after the device has been electrically disconnected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method, comprising:
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detecting whether a device coupled to a host controller is in an active state; if the device is not in an active state, electrically disconnecting the device from a host controller, wherein electrically disconnecting the device from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; if the device is in an active state, maintaining an electrical connection between the device and the host controller; and electrically reconnecting the device using a sideband signal after the device has been electrically disconnected. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A system, comprising:
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a processor; a host controller coupled to the processor; a device detect logic; a hub electrically coupled to the host controller and device detect logic; an auto detach logic coupled to the hub; and wherein the auto detach logic initiates an electrical disconnect of the hub from the host controller if the device detect logic does not detect a device on the hub, and wherein the hub being electrically disconnected from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and wherein a sideband signal is used to signal the device to electrically reconnect after the device has been electrically disconnected. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A method, comprising:
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detecting whether a device is coupled to a hub; if a device is not coupled to the hub, electrically disconnecting the hub from a host controller, wherein electrically disconnecting the hub from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and if a device is coupled to the hub, maintaining a connection between the hub and the host controller; and electrically reconnecting the hub using a sideband signal after the hub has been electrically disconnected. - View Dependent Claims (40, 41, 42, 43, 44)
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45. A computer accessible memory medium that stores program instructions, wherein the program instructions are executable by a processor to:
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detect whether a device coupled to a host controller is in an active state; if the device is not in an active state, electrically disconnect the device from a host controller, wherein electrically disconnecting the device from the host controller causes an appearance to the host controller that a device is not coupled to the host controller; and if the device is in an active state, maintain an electrical connection between the device and the host controller; and electrically reconnect the device using a sideband signal after the device has been electrically disconnected. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56)
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57. A system, comprising:
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a processor; a host controller coupled to the processor; and a device coupled to the host controller; wherein the device is electrically disconnected from the host controller if the device is not in an active state; and wherein a sideband signal is used to signal the device to electrically reconnect after the device has been electrically disconnected. - View Dependent Claims (58, 59, 60, 61)
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62. A system, comprising:
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a processor; a host controller coupled to the processor; and a card reader coupled to the host controller; wherein when a memory card is removed from the card reader, the card reader is electrically disconnected from the host controller; and wherein the card reader being electrically disconnected from the host controller causes an appearance to the host controller that the card reader is not coupled to the host controller; wherein a sideband signal is used to signal the card reader to electrically reconnect after the card reader has been electrically disconnected. - View Dependent Claims (63, 64, 65, 66, 67, 68)
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69. A method, comprising:
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detecting whether a card reader coupled to a host controller is in an active state; if the card reader does not have a memory card inserted in the card reader, electrically disconnecting the card reader from a host controller, wherein electrically disconnecting the card reader from the host controller causes an appearance to the host controller that the card reader is not coupled to the host controller; and if the card reader is in an active state, maintaining an electrical connection between the card reader and the host controller; wherein a sideband signal is used to signal the card reader to electrically reconnect when an attempt is made to access a card after the card reader has been electrically disconnected with a card inserted into the card reader. - View Dependent Claims (70, 71, 72, 73)
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74. A computer accessible memory medium that stores program instructions, wherein the program instructions are executable by a processor to perform:
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detecting whether a card reader coupled to a host controller is in an active state; if the card reader does not have a memory card inserted in the card reader, electrically disconnecting the device from a host controller, wherein electrically disconnecting the card reader from the host controller causes an appearance to the host controller that the card reader is not coupled to the host controller; and if the card reader is in an active state, maintaining an electrical connection between the card reader and the host controller; wherein a sideband signal is used to signal the card reader to electrically reconnect when an attempt is made to access a card after the card reader has been electrically disconnected with a card inserted into the card reader. - View Dependent Claims (75, 76, 77, 78)
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79. A method, comprising:
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detecting whether a device coupled to a host controller is in an active state, wherein the device is a hub, and the active state comprises a second device coupled to the hub; if the device is not in an active state, electrically disconnecting the device from a host controller, wherein electrically disconnecting the device from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and if the device is in an active state, maintaining an electrical connection between the device and the host controller; wherein the second device is coupled to the hub and a sideband signal from a computer signals the hub to electrically disconnect and wherein a sideband signal from the computer signals the hub to electrically reconnect at a later time.
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80. A method, comprising:
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detecting whether a device coupled to a host controller is in an active state, wherein the device is a hub, and the active state comprises a second device coupled to the hub; if the device is not in an active state, electrically disconnecting the device from a host controller, wherein electrically disconnecting the device from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and if the device is in an active state, maintaining an electrical connection between the device and the host controller; wherein the second device is coupled to the hub and a sideband signal from a computer signals the hub to enter a reduced functionality state and wherein a sideband signal from the computer signals the hub to exit the reduced functionality state at a later time.
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81. A method, comprising:
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detecting whether a device coupled to a host controller is in an active state, wherein the device is a card reader, and wherein the card reader is not in an active state if the card reader has not been accessed in a second specified amount of time; if the device is not in an active state, electrically disconnecting the device from a host controller, wherein electrically disconnecting the device from the host controller causes an appearance to the host controller that the device is not coupled to the host controller; and if the device is in an active state, maintaining an electrical connection between the device and the host controller; electrically reconnecting the card reader using a sideband signal when an attempt is made to access a card after the card reader has been electrically disconnected with a card inserted into the card reader.
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82. A computer accessible memory medium that stores program instructions, wherein the program instructions are executable by a processor to:
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detect whether a card reader coupled to a host controller is in an active state; if the card reader is not in an active state, electrically disconnect the card reader from a host controller, wherein electrically disconnecting the card reader from the host controller causes an appearance to the host controller that a card reader is not coupled to the host controller; and if the card reader is in an active state, maintain an electrical connection between the device and the host controller; wherein a sideband signal is used to signal the card reader to electrically reconnect when an attempt is made to access a card after the card reader has been electrically disconnected with a card inserted into the card reader.
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Specification