Method and apparatus for power managing display devices
AssigneeIntel Corporation
InventorNilesh V. Shah
Life of this patent
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Abstract
An embodiment of a graphics controller includes a clock output circuit to output a clock signal and also includes a display device control signal input/output circuit to output a display device control signal. The graphics controller further includes a display device data bus input/output circuit to output an encoded information on a display device data bus when the display device control signal output circuit asserts the display device control signal, the encoded information to represent a power management state.
Claims21
An apparatus for communicating power management information between a computer system and an external display device, comprising:
- a clock output circuit to output a clock signal;
- a display device control signal input/output circuit to output a display device control signal upon a request from an operating system of the computer system to place the display device in a power management state, the power management state including an advanced configuration and power interface (ACPI) state, the display device control signal selected from a plurality of display device control signals;
- and
- a display device data bus input/output circuit to output an encoded information on a display device data bus when the display device control signal output circuit asserts the display device control signal, the encoded information to represent a power management state, the display device data bus including an eight bit data path, the ACPI state encoded on a least significant two bits of the eight bit data path.
A method for communicating power management information between a computer system and an external display device, comprising:
- outputting a clock signal from a graphics controller;
- asserting a display device control signal from the graphics controller for a duration of at least two clock periods upon a request from an operating system of the computer system to place the display device in a power management state, the power management state including an advanced configuration and power interface (ACPI) state, the display device control signal selected from a plurality of display device control signals;
- and
- outputting an encoded information from the graphics controller to a display device on a display device data bus while asserting the display device control signal, the encoded information to represent a power management state, the display device data bus including an eight bit data path, the ACPI state encoded on a least significant two bits of the eight bit data path.
A system for communicating power management information between a computer system and an external display device, comprising:
- a display device electrically coupled to a display device data bus and further coupled to a display device control signal line and a clock signal line;
- a graphics controller including a clock output circuit to output a clock signal on the clock signal line;
- a display device control signal input/output circuit to output a display device control signal on the display device control signal line upon a request from an operating system of the computer system to place the display device in a power management state, the power management state including an advanced configuration and power interface (ACPI) state, the display device control signal selected from a plurality of display device control signals;
- and
- a display device data bus input/output circuit to output an encoded information on the display device data bus when the display device control signal output circuit asserts the display device control signal, the encoded information to represent a power management state, the display device data bus including an eight bit data path, the ACPI state encoded on a least significant two bits of the eight bit data path.
Dependencies are inferred from the claim text.