Abstract:
Methods and apparatus for adjusting the operation of a display device so as to be at least within prescribed form factor or other constraints. In one embodiment of the invention, various operational parameters for a display element are adjusted based on considerations specific to high density form factor constraints. For example, in one such device, a Low Power DisplayPort (LPDP) device having a LPDP source and sink adjust the data rate of the visual data to minimize power consumption while still properly supporting display panel resolutions. In some embodiments, the LPDP source and sink may adjust the transceiver voltages to minimize power consumption. In an alternate embodiment, an LPDP device adjusts data rates to minimize the effects of platform noise. In another aspect of the invention, various display elements of a device coordinate quiescent (“quiet”) mode operation during periods of inactivity.
Abstract:
The same pixel stream may be displayed on an internal display and an external display while maintaining the original aspect ratio corresponding to the internal display dimensions. A connector with limited number of pins may only support a two-wire display port interface to the external display, which may not provide enough bandwidth to transmit the full resolution image to the external display. To transmit the full resolution image, a color space conversion from RGB space to YCbCr color space may be performed. The Luma component may be transmitted at full resolution, while the chroma components may be scaled. Accordingly, there is no loss of image resolution, while some amount of color resolution may be lost. However, there is no need to retime frames within the system on chip (SOC), and the same pixel stream may be used as the basis for display on both the internal and the external display.
Abstract:
One embodiment of the present invention sets forth a system for generating multiple video output signals from a single video pipeline within a graphics processing unit. Pixel data from more than one display surface is retrieved and multiplexed before being transmitted to a video pipeline for processing. The resulting video pixel data is routed to video output encoders, which selectively accept the video pixel data for transmission to attached display devices.
Abstract:
In an embodiment, a host computing device includes an internal display and also includes a connector to connect to an external display. A cable is provided to connect to the connector and to connect to the external display. The cable includes video processing capabilities. For example, the cable may include a memory configured to store a frame buffer. The frame buffer may store a frame of video data for further processing by the video processing device in the cable. The video processing device may manipulate the frame in a variety of ways, e.g. scaling, rotating, gamma correction, dither correction, etc.
Abstract:
A system and method for efficiently allocating data in a memory hierarchy. A system includes a memory controller for controlling accesses to a memory and a display controller for processing video frame data. The memory controller includes a cache capable of storing data read from the memory. A given video frame may be processed by the display controller and presented on a respective display screen. During processing, control logic within the display controller sends multiple memory access requests to the memory controller with cache hint information. For the frame data, the cache hint information may alternate between (i) indicating to store frame data read in response to respective requests in the memory cache and (ii) indicating to not store the frame data read in response to respective requests in the memory cache.
Abstract:
In an embodiment, hardware implementing a transcendental or other non-linear function is based on a series expansion of the function. For example, a Taylor series expansion may be used as the basis. One or more of the initial terms of the Taylor series may be used, and may be implemented in hardware. In some embodiments, modifications to the Taylor series expansion may be used to increase the accuracy of the result. In one embodiment, a variety of bit widths for the function operands may be acceptable for use in a given implementation. A methodology for building a library of series-approximated components for use in integrated circuit design is provided which synthesizes the acceptable implementations and tests the results for accuracy. A smallest (area-wise) implementation which produces a desired level of accuracy may be selected as the library element.
Abstract:
Devices and methods for dynamic dithering are provided. For example, an electronic device according to an embodiment may include image processing circuitry that operates on higher-bit-depth image data and a display panel that displays lower-bit-depth image data. To obtain the lower-bit-depth image data, the image processing circuitry may perform dynamic dithering on the higher-bit-depth image data. Such dynamic dithering may involve dithering frames of the higher-bit-depth image data based at least in part on respective rounding threshold values.
Abstract:
A system and method for efficiently scheduling memory access requests. A semiconductor chip includes a memory controller for controlling accesses to a shared memory and a display controller for processing frame data. In response to detecting an idle state for the system and the supported one or more displays, the display controller aggregates memory requests for a given display pipeline of one or more display pipelines prior to attempting to send any memory requests from the given display pipeline to the memory controller. Arbitration may be performed while the given display pipeline sends the aggregated memory requests. In response to not receiving memory access requests from the functional blocks or the display controller, the memory controller may transition to a low-power mode.
Abstract:
A method and apparatus for changing a frequency of a clock signal to avoid interference is disclosed. In one embodiment, data conveyed on a first interface is synchronized to a clock signal at a first frequency. Signals are conveyed on a second interface at another frequency. Responsive to a change of the frequency at which signals are conveyed on a second interface, a clock control unit associated with the first interface initiates a change of the clock signal to a second frequency. The second frequency may be chosen as to not cause interference with the frequency at which signals are conveyed on the second interface. The change of the clock frequency may be performed in such a manner as to prevent spurious activity on the clock line of the interface.
Abstract:
A method and apparatus for changing a frequency of a clock signal to avoid interference is disclosed. In one embodiment, data conveyed on a first interface is synchronized to a clock signal at a first frequency. Signals are conveyed on a second interface at another frequency. Responsive to a change of the frequency at which signals are conveyed on a second interface, a clock control unit associated with the first interface initiates a change of the clock signal to a second frequency. The second frequency may be chosen as to not cause interference with the frequency at which signals are conveyed on the second interface. The change of the clock frequency may be performed in such a manner as to prevent spurious activity on the clock line of the interface.