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Patent Issued for Method and Apparatus to Support a Self-Refreshing Display Device Coupled to a Graphics Controller

June 19, 2014



By a News Reporter-Staff News Editor at Computer Weekly News -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Wyatt, David (San Jose, CA); Dewey, Thomas E. (Menlo Park, CA), filed on March 31, 2011, was published online on June 3, 2014.

The patent's assignee for patent number 8745366 is NVIDIA Corporation (Santa Clara, CA).

News editors obtained the following quote from the background information supplied by the inventors: "The invention relates generally to display systems and, more specifically, to a method and apparatus to support a self-refreshing display device coupled to a graphics controller.

"Some recently designed display devices include a self-refresh capability, where the display device includes a local controller configured to generate video signals from a static, cached frame of digital video independently from the graphics controller. When in such a self-refresh mode, the video signals are driven by the local controller, thereby allowing portions of a parallel processing system, such as the graphics controller and a communications bus, to be placed in a deep sleep state to conserve power. Once in self-refresh mode, when the image to be displayed needs to be updated, control may be transitioned back to the graphics controller to allow new video signals to be generated based on a new set of pixel data.

"Conventional systems are configured to initialize the various interconnected components in a serial manner. For example, the central processing unit may first cause a driver to make a call to wake-up the communications bus. An initialization routine is run to configure the communications bus. Once the communications bus is operating in a normal state, the central processing unit may then cause a driver to make a call to wake-up the graphics controller. The graphics driver then sends commands via the communications bus to the graphics controller to initialize the graphics controller.

"One drawback to the above described technique is that each component of the parallel processing subsystem must be initialized in order before the next component can begin its initialization process. For example, while the communications bus is initialized, the graphics controller may sit idle waiting to receive commands over the communications bus. The described technique fails to minimize the number of clock cycles in which the graphics driver is initialized upon waking from a deep sleep state. Extended initialization routines may lead to latency in graphics updates and could be distracting to a user of the computer system when entering and exiting a panel self-refresh mode.

"As the foregoing illustrates, what is needed in the art is an improved technique for waking-up the graphics controller from a deep sleep state."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "One embodiment of the present invention sets forth a method for setting the operating state for a graphics processing unit coupled to a self-refreshing display device. The method includes the step of performing at least one operation to set a first portion of the operating state for the graphics processing unit. The method further includes the steps of determining whether a signal has been asserted indicating that the graphics processing unit should perform a warm-boot operation and, if the signal has been asserted, then performing the warm-boot operation to set a second portion of the operating state for the graphics processing unit or, if the signal has not been asserted, then performing a cold-boot operation to set the second portion of the operating state for the graphics processing unit.

"One advantage of the disclosed technique is that minimizing the configuration time for a graphics processing unit may decrease latency associated with updating an image being displayed while the display device is operating in a panel self-refresh mode. A computer system that includes a display device having a self-refresh capability may frequently cause a graphics processing unit to enter and exit a deep sleep state. Many times, the graphics processing unit will exit the deep sleep state within a few seconds of entering the deep sleep state. Therefore, it is very unlikely that the configuration of the computer system has changed since the graphics processing unit entered the deep sleep state. The disclosed technique exploits this fact by saving and loading the operating state of the graphics processing unit rather than relying on the graphics driver to configure the graphics processing unit each time the power for the graphics processing unit is switched on.

"Another advantage of the disclosed technique is that the graphics processing unit may be configured in parallel with other hardware and software components of the computer system. Utilizing an auxiliary communications path or a dedicated, non-volatile memory to load instructions used to configure the graphics processing unit relieves the graphics processing unit from being dependent on the successful initialization of a high speed communications bus, such as the PCIe bus, before the configuration of the graphics processing unit can proceed. Enabling the graphics processing unit to be configured independently reduces the time required for initialization and provides a better user experience."

For additional information on this patent, see: Wyatt, David; Dewey, Thomas E.. Method and Apparatus to Support a Self-Refreshing Display Device Coupled to a Graphics Controller. U.S. Patent Number 8745366, filed March 31, 2011, and published online on June 3, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8745366.PN.&OS=PN/8745366RS=PN/8745366

Keywords for this news article include: NVIDIA Corporation.

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Source: Computer Weekly News


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