Abstract: A dither unit with a programmable kernel matrix in which each indexed location/entry may store one or more dither values. Each dither value in a respective entry of the kernel matrix may correspond to the number of bits that are truncated during dithering. During dithering of each pixel of an image, entries in the kernel matrix may be indexed according to the relative coordinates of the pixel within the image. A dither value for the pixel may be selected from the indexed entry based on the truncated least significant bits of the pixel component value. When the kernel matrix is storing more than one dither value per entry, the dither value may be selected based further on the number of truncated least significant bits. A dithered pixel component value may then be generated according to the dither value and the remaining most significant bits of the pixel component value.

Abstract: An inline scaling unit configured to retime an input video frame is disclosed. The scaling unit is configured to receive pixels within a line of a video frame to be displayed on a primary display that is within a first clock domain. The scaling unit down-scales the group of pixels and writes the down-scaled pixels to a buffer circuit in the first clock domain. The scaling unit includes a control circuit configured to generate horizontal and vertical control signals for the retimed video frame to be displayed on a secondary display that is within a second clock domain. The horizontal and vertical control signals are then used to enable reading from the buffer circuit in the second clock domain. The scaling unit outputs the down-scaled pixels and the generated control signals within the retimed video frame such that input video frame and the retimed video frame may be displayed concurrently.

Abstract: A scaling unit is disclosed that is within a computing device having an internal display and an external interface. The scaling unit facilitates the concurrent presentation of images on the internal display and an external display connected to the external interface. In configurations in which the external interface does not have sufficient data width to concurrently display images on the external display at the same resolution as the internal display, the scaling unit may be used to reduce the number of pixels in a line, thus reducing bandwidth requirements at the external interface. The scaling unit may also scale further to maintain an aspect ratio of the image displayed on the internal display. Further vertical scaling may be performed outside the computing device (e.g., by a dongle coupled between the computing device and the external display), such that the scaling unit may be implemented with reduced memory requirements.

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: 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: A method of displaying an image includes generating a contract in the display engine, transferring the contract to the memory controller before the end of a sweep, generating a contract amendment in response to changes in the display engine, transferring the contract amendment to the memory controller, making a decision whether the contract amendment can be processed, fetching data from the memory controller according to the contract incorporating the contract amendment if the decision is that the contract amendment can be processed, sending the fetched data to the display engine in an isochronous stream; and processing the fetched data using the display engine.

Abstract: In an embodiment, one or more fabric control circuits may be inserted in a communication fabric to control various aspects of the communications by components in the system. The fabric control circuits may be included on the interface of the components to the communication fabric, in some embodiments. In other embodiments that include a hierarchical communication fabric, fabric control circuits may alternatively or additionally be included. The fabric control circuits may be programmable, and thus may provide the ability to tune the communication fabric to meet performance and/or functionality goals.

Abstract: A circuit for data stream buffer management, lane alignment, and clock compensation of data transfers across a clock boundary using a single first in first out (FIFO) buffer in each serial channel is described. The RapidIO® data channel, for example, operates using a clock recovered from the data stream. The RapidIO® data stream has embedded special characters, where a select sequence of embedded characters is a clock compensation pattern. A look ahead circuit is used to detect the clock compensation pattern early and generate a clock compensation indicator signal. The FIFO writes data and the associated clock compensation indicator signal in a clock compensation indicator bit in synchronism with the recovered clock. A read circuit using a second clock of a different frequency than the first clock reads data and clock compensation bits from the FIFO and generates an almost empty signal when appropriate. A multiplexer is used at the FIFO output to pad data to the system interface.

Abstract: A method of displaying an image includes generating a contract in the display engine, transferring the contract to the memory controller before the end of a sweep, generating a contract amendment in response to changes in the display engine, transferring the contract amendment to the memory controller, making a decision whether the contract amendment can be processed, fetching data from the memory controller according to the contract incorporating the contract amendment if the decision is that the contract amendment can be processed, sending the fetched data to the display engine in an isochronous stream; and processing the fetched data using the display engine.

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: 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: A graphics system may include a display pipe with a buffer configured to store pixels to be processed by a display controller for displaying on a display device, with a buffer control circuit coupled to the buffer to supply pixels to the display controller. When the buffer control circuit detects an underrun of the buffer responsive to the display controller attempting to read pixels from the buffer that have not yet been written to the buffer, the buffer control circuit may supply an underrun pixel to the display. The underrun pixel may be selected from a set of previously stored set of underrun pixels, which may include a most recent valid pixel read by the display controller. A read pointer representative of the location in the buffer from where the display controller is currently attempting to read may be advanced even when an underrun condition occurs.

Abstract: Apparatus, system, and method for detecting AC-coupled electrical loads of a set of digital-to-analog converters are described. In one embodiment, a processing apparatus includes a digital-to-analog converter. The processing apparatus also includes a pulse generation module connected to the digital-to-analog converter, and the pulse generation module is configured to direct the digital-to-analog converter to transmit a pulse of electrical energy. The processing apparatus further includes a load detection module connected to the digital-to-analog converter, and the load detection module is configured to determine a connection status of the digital-to-analog converter based on a degree to which the pulse of electrical energy is reflected during a transient response time period.

Abstract: Multiple display heads of a single graphics processor are exploited to perform antialiasing and other processing tasks. In one embodiment, two display heads of the same graphics processor are coupled to each other in a master/slave configuration via a pixel transfer path. The “master” display head receives pixels from the “slave” display head in addition to its own pixels, and pixel selection logic in the master display head can blend the two pixels or select either one to the exclusion of the other. If the two pixels correspond to different sampling locations in the same display pixel, the blended pixel is an antialiased pixel.

Abstract: Apparatus, system, and method for arbitrating between memory requests are described. In one embodiment, a processing apparatus includes a memory request generator configured to generate memory requests specifying data for respective presentation elements. The memory request generator is configured to assign priorities to the memory requests based on a presentation order of the presentation elements. The processing apparatus also includes a memory request arbiter connected to the memory request generator. The memory request arbiter is configured to issue the memory requests based on the priorities assigned to the memory requests.

Abstract: A graphics processing apparatus includes an output pipeline including a set of memory clients. The graphics processing apparatus also includes a memory controller connected to the output pipeline. The memory controller is configured to retrieve data requested by respective ones of the memory clients from a memory. The graphics processing apparatus further includes a buffering module connected between the memory controller and the output pipeline. The buffering module includes a buffer including a buffering space shared by the memory clients. The buffering module also includes a buffer controller connected to the buffer. The buffer controller is configured to: (1) dynamically assign portions of the buffering space to respective ones of the memory clients; (2) coordinate storage of the data in the assigned portions; and (3) coordinate delivery of the data from the assigned portions to respective ones of the memory clients.

Abstract: Apparatus, system, and method for delivering data to multiple memory clients are described. In one embodiment, a graphics processing apparatus includes an output pipeline including a set of memory clients. The graphics processing apparatus also includes a memory controller connected to the output pipeline. The memory controller is configured to retrieve data requested by respective ones of the set of memory clients from a memory. The graphics processing apparatus further includes a buffering module connected between the memory controller and the output pipeline. The buffering module includes a unitary buffer and a buffer controller connected to the unitary buffer. The buffer controller is configured to coordinate storage of the data in the unitary buffer, and the buffer controller is configured to coordinate delivery of the data from the unitary buffer to respective ones of the set of memory clients.

Abstract: A circuit for data stream buffer management, lane alignment, and clock compensation of data transfers across a clock boundary using a single first in first out (FIFO) buffer in each serial channel is described. The RapidIO® data channel, for example, operates using a clock recovered from the data stream. The RapidIO® data stream has embedded special characters, where a select sequence of embedded characters is a clock compensation pattern. A look ahead circuit is used to detect the clock compensation pattern early and generate a clock compensation indicator signal. The FIFO writes data and the associated clock compensation indicator signal in a clock compensation indicator bit in synchronism with the recovered clock. A read circuit using a second clock of a different frequency than the first clock reads data and clock compensation bits from the FIFO and generates an almost empty signal when appropriate. A multiplexer is used at the FIFO output to pad data to the system interface.