Handling of multiple compliant and non-compliant wake-up sources in a computer system
First Claim
1. A computer system that comprises:
- an expansion bus that includes a plurality of expansion bus signals;
a bus bridge coupled to the expansion bus; and
a signal gate configurable to isolate the bus bridge from one of the expansion bus signals.
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Accused Products
Abstract
A system and method are disclosed for handling devices that assert a wake-up signal in an improper fashion. It is observed that any wake-up signals that remain asserted as the computer system enters a low-power mode are likely produced by non-compliant cards, and to assure proper functioning of the system, it is desirable for the computer system to selectively block assertion of asserted signals from non-compliant cards. In one embodiment the computer system includes an expansion bus coupled to a bus bridge, and a signal gate. The expansion bus includes a wake-up signal that the signal gate can be configured to isolate from the bus bridge. The signal gate is preferably controlled by the power management controller. The power management controller sets the signal gate to isolate the signal from the bus bridge if the controller determines that wake-up signal is being driven in a non-standard manner. The non-compliance may be determined by: (a) detecting a transition of the computer to a reduced power state; (b) pausing for a predetermined delay; and (c) sampling the wake-up signal to identify any asserted wake-up signals. In the presence of non-compliant expansion cards, the disclosed embodiments may advantageously assure correct operation of the system with minimal additional cost.
30 Citations
20 Claims
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1. A computer system that comprises:
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an expansion bus that includes a plurality of expansion bus signals;
a bus bridge coupled to the expansion bus; and
a signal gate configurable to isolate the bus bridge from one of the expansion bus signals. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A computer system that comprises:
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a user input device;
a computer chassis that contains at least;
a system memory configured to store an operating system;
a central processor coupled to the memory and configured to execute the operating system;
an expansion bus that couples the user input device to the central processor;
a bus bridge coupled to the expansion bus, wherein the bus bridge includes;
a power management controller coupled to the expansion bus and configured to receive a wake-up signal from a device resident on the expansion bus, wherein the power management controller isolates the wake-up signal from the bus bridge device if the device drives the wake-up signal in a non-compliant manner. - View Dependent Claims (8, 9, 10)
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11. A method for handling non-compliant devices in a computer, wherein the method comprises:
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detecting a transition of the computer to a reduced-power state;
pausing for a predetermined delay;
sampling one or more wake-up signals from one or more devices;
establishing a signal block against any asserted wake-up signals. - View Dependent Claims (12, 13, 14, 15)
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16. A computer system that comprises:
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an expansion bus that includes a plurality of expansion bus signals;
a bus bridge coupled to the expansion bus; and
a controller coupled to receive at least one of the expansion bus signals and configured to provide a gated signal to the bus bridge, wherein the gate signal is asserted only if an received expansion bus signal is asserted and not blocked. - View Dependent Claims (17, 18, 19, 20)
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Specification