# US 8,542,240 B2 · Electronic device having switchable graphics processors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,240 B2 - Document ID: US8542240B2 - Status: Granted - Kind: B2 - Application number: 12/798,073 - Filed: 2010-03-29 - Published: 2010-09-30 - Granted: 2013-09-24 - Earliest claimed: 2010-03-29 - Assignees: Intel Corporation - Applicants: Siddhartha Nath - Inventors: Siddhartha Nath - Web page: https://patentgrep.com/patent/US8542240B2 ## CPC - G06F 15/177: Initialisation or configuration control {(processor initialisation G06F9/4405)} - G09G 5/006: {Details of the interface to the display terminal (specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04)} - G09G 5/363: {Graphics controllers} - G09G 2310/0275: Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current - G09G 2360/06: Use of more than one graphics processor to process data before displaying to one or more screens - G09G 2370/04: Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller - G09G 2370/042: for monitor identification - G09G 2370/14: Use of low voltage differential signaling [LVDS] for display data communication - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract An electronic device comprises at least two graphics processors, referred to herein as an integrated graphics processor and a discrete graphics processor. In some circumstances, the device may be switched between the integrated graphics processor and the discrete graphics processor. In some embodiments, techniques are implemented to lock temporarily the screen display on the output of a controller while the device executes a switch between graphics processors, thereby eliminating, or at least reducing, the presence of a blank output display on the electronic device. Other embodiments may be described. ## Claims ### Claim 1 A method to switch between a discrete graphics processor and an integrated graphics processor in an electronic device, comprising: switching an I2C multiplexer from the discrete graphics processor to the integrated graphics processor; switching a graphics output mode from the discrete graphics processor to the integrated graphics processor; and locking a display on the output of the discrete graphics processor; falsely reporting, to an operating system executing on the electronic device, a successful transition from the discrete graphics processor to the integrated graphics processor by writing success indicators to at least one render device driver interface and at least one display device driver interface; and switching a display multiplexer from the discrete graphics processor to the integrated graphics processor after the integrated graphics processor has completed rendering an output. ### Claim 2 (depends on 1) The method of claim 1, wherein the I2C multiplexer comprises unique input/output pins coupled to the integrated graphics processor and wherein switching an I2C multiplexer from the discrete graphics processor to the integrated graphics processor comprises disconnecting one or more input/output pins from the discrete graphics processor and connecting one or more input/output pins to the integrated graphics processor. ### Claim 3 (depends on 1) The method of claim 1, wherein locking a display on the output of the discrete graphics processor further comprises blocking a screen refresh operation in an operating system executing on the electronic device, such that a blank screen is not presented on the display. ### Claim 4 (depends on 1) The method of claim 1, wherein locking a display on the output of the discreet graphics processor further comprises blocking a graphics driver from accessing a memory module. ### Claim 5 An electronic device, comprising: a processor; a display; a discrete graphics processor and an integrated graphics processor; a memory module; and logic instructions stored in a computer readable medium which, when executed by the processor, configure the processor to switch between a discrete graphics processor and an integrated graphics processor in an electronic device by performing operations, comprising: switching an I2C multiplexer from the discrete graphics processor to the integrated graphics processor; switching a graphics output mode from the discrete graphics processor to the integrated graphics processor; and locking a display on the output of the discreet graphics processor; falsely reporting, to an operating system executing on the electronic device, a successful transition from the discrete graphics processor to the integrated graphics processor by writing success indicators to at least one render device driver interface and at least one display device driver interface; and switching a display multiplexer from the discrete graphics processor to the integrated graphics processor after the integrated graphics processor has completed rendering an output. ### Claim 6 (depends on 5) The electronic device of claim 5, further comprising logic instructions stored in a computer readable medium which, when executed by the processor, configure the processor to disconnect one or more input/output pins from the discrete graphics processor and connecting one or more input/output pins to the integrated graphics processor. ### Claim 7 (depends on 5) The electronic device of claim 5, further comprising logic instructions stored in a computer readable medium which, when executed by the processor, configure the processor to block a screen refresh operation in an operating system executing on the electronic device. ### Claim 8 (depends on 5) The electronic device of claim 5, further comprising logic instructions stored in a computer readable medium which, when executed by the processor, configure the processor to block a graphics driver from accessing a memory module. ### Claim 9 A method to switch between an integrated graphics processor and a discrete graphics processor in an electronic device, comprising: switching an I2C multiplexer from the integrated graphics processor to the discrete graphics processor; initiating a plug-n-play start operation on the discrete graphics processor; switching a graphics output mode from the integrated graphics processor to the discrete graphics processor; and locking a display on the output of the integrated graphics processor; falsely reporting, to an operating system executing on the electronic device, a successful transition from the integrated graphics processor to the discrete graphics processor by writing success indicators to at least one render device driver interface and at least one display device driver interface; and switching a display multiplexer from the integrated graphics processor to the discrete graphics processor after the integrated graphics processor has completed rendering an output. ### Claim 10 (depends on 9) The method of claim 9, wherein the I2C multiplexer comprises unique input/output pins coupled to the integrated graphics processor and wherein switching an I2C multiplexer from the integrated graphics processor to the discrete graphics processor comprises disconnecting one or more input/output pins from the integrated graphics processor and connecting one or more input/output pins to the discrete graphics processor. ### Claim 11 (depends on 9) The method of claim 9, wherein locking a display on the output of the integrated graphics processor further comprises blocking a screen refresh operation in an operating system executing on the electronic device. ### Claim 12 (depends on 9) The method of claim 9, wherein locking a display on the output of the integrated graphics processor further comprises blocking a graphics driver from accessing a memory module. ### Claim 13 An electronic device, comprising: a processor; a display; a discrete graphics processor and an integrated graphics processor; a memory module; and logic instructions stored in a computer readable medium which, when executed by the processor, configure the processor to switch between an integrated graphics processor and a discrete graphics processor in an electronic device by performing operations, comprising: switching an I2C multiplexer from the integrated graphics processor to the discrete graphics processor; initiating a plug-n-play start operation on the discrete graphics processor; switching a graphics output mode from the integrated graphics processor to the discrete graphics processor; and locking a display on the output of the integrated graphics processor; falsely reporting, to an operating system executing on the electronic device, a successful transition from the integrated graphics processor to the discrete graphics processor by writing success indicators to at least one render device driver interface and at least one display device driver interface; and switching a display multiplexer from the integrated graphics processor to the discrete graphics processor after the integrated graphics processor has completed rendering an output. ### Claim 14 (depends on 13) The electronic device of claim 13, wherein the I2C multiplexer comprises unique input/output pins coupled to the discrete graphics processor and wherein switching an I2C multiplexer from the discrete graphics processor to the integrated graphics processor comprises disconnecting one or more input/output pins from the discrete graphics processor and connecting one or more input/output pins to the integrated graphics processor. ### Claim 15 (depends on 13) The electronic device of claim 13, wherein locking a display on the output of the discrete graphics processor further comprises blocking a screen refresh operation in an operating system executing on the electronic device. ### Claim 16 (depends on 13) The electronic device of claim 13, wherein locking a display on the output of the discrete graphics processor further comprises blocking a graphics driver from accessing a memory module.