Abstract: A graphics system comprising a plurality of rendering pipelines and a scheduling network. Each rendering pipeline couples to the scheduling network, and includes a media processor, a rendering unit and a memory. A communication bus may couple the scheduling network and the memory of each rendering pipeline. The media processor in each rendering pipeline may direct the saving of state information of the corresponding rendering pipeline to the corresponding memory in response to receiving a corresponding context switch indication. A first of the media processors initiates the transfer of a resume token to the scheduling network through the corresponding rendering pipeline if the context switch occurs during an ordered processing mode. The scheduling network unblocks one or more rendering pipelines other than the first rendering pipeline in response to receiving the resume token.

Abstract: A system and method are disclosed to allow the tiling of sample jitter patterns to be independent of the tiling of clustered graphics accelerators. Each accelerator uses an x,y “bias” offset to shift the origin of the jitter pattern within the sample space region addressed by the accelerator. In this way, multiple accelerators may be programmed so that their jitter patterns integrate into one global pattern without discontinuities at the region boundaries.

Abstract: A dithering system comprising a dithering unit, a storage medium, and an averaging unit. The dithering unit is configured to receive a set of data values, to add dither values to the data values, and to truncate the resultant addition values to L-bit truncated values. The storage medium is configured to store the L-bit truncated values. The averaging unit is configured to read the L-bit truncated values from the storage medium, and to compute an average value using at least a subset of the L-bit truncated values. The dither values may have an average value of approximately one-half. The dither values may approximate a uniform distribution of numbers between ?A+½ and A+½, wherein A is greater than or equal to one. Alternatively, the dithering unit may receive a temporal stream of data values, and the average unit may perform a temporal average (e.g. an FIR filter). The dithering system may be incorporated in a graphics system. In this case, data values may represent rendered sample values (e.g.

Abstract: A system and method are disclosed for reproducing a pre-selected larger 2-D sample location pattern from a smaller one by means of X,Y address permutation. This method, for example, allows hardware to effectively reproduce a pre-selected set of sample locations for an array of 128×128 sample bins from a smaller set of pre-selected sample locations for an array of 2×2 sample bins. A permutation logic unit may use a first portion of an address for a sample bin B to identify a corresponding 2-D transformation, apply the inverse of the transformation to a second portion of the sample bin address to identify the corresponding bin of the 2×2 array of sample bins, and apply the transformation to the sample locations stored in the corresponding bin to reproduce the sample locations pre-selected for sample bin B.

Abstract: A video routing system including video routers VR(0), VR(1), . . . , VR(NR−1) coupled in a linear series. Each video router in the linear series successively operates on a digital video stream. Each video router provides a synchronous clock with its output video stream so a link interface buffer in the next video router can capture values from the output video stream in response to the synchronous clock. Each video router buffers a common clock to generate a local output clock. The output clock is used as a read clock to read data out of the corresponding link interface buffer. The output clock is also used to generate the synchronous clock that is transmitted downstream. To initialize the series, reset is sequentially removed from each video router starting from the first video router after the common clock has stabilized.

Abstract: A system and method is disclosed for management of sample data to enable video rate anti-aliasing convolution. Sample data may be moved simultaneously from a sample buffer to a bin scanline cache and from the bin scanline cache to an array of N2 processor—memory units (e.g. 25 for N=5). Pixel data may be convolved from an N×N sample bin array that may be approximately centered on the pixel location. Since each sample bin contains Ns/b samples, Ns/b×N2 samples may be filtered for each pixel (e.g. 400 for N=5 and Ns/b=16). Each processor—memory unit convolves the sample data for one sample bin in the N×N sample bin array and supports a variety of filter functions. Pixel data may be output to a real time video data stream.

Abstract: A graphics system comprising a control unit and a series of calculation units coupled together in a closed chain by a segmented communication bus. The calculation unit collaboratively generate one or more video signals. Each calculation unit is programmably assigned to contribute its locally-generated pixels to one of the video streams. The control unit sends a frame readback request to a selected one of the calculation units through the segmented communication bus. The frame readback request specifies some subset of the pixels in one of the video streams for readback to the control unit. In response to the frame readback request, the selected calculation unit transmits the subset of pixels of the specified video stream to the control unit, and the control unit forwards the subset of pixels to a target memory block (e.g. in system memory of a host computer or memory within the graphics system).

Abstract: A graphics system that is configured to synchronize a slave display channel to a master display channel may include a master display timing generator configured to provide a frame event indication and a slave display timing generator. The slave display timing generator may be configured to receive the frame event indication and, in response to receiving the frame event indication during its active display period, the slave display timing generator may be configured to wait until its current active display period ends and then jump to its synchronization point. Alternatively, the slave display timing generator may be configured to jump to its synchronization point immediately or after the end of the current horizontal line, and any remaining display information in an interrupted frame may be displayed during the next active display period.

Abstract: A computer graphics system that utilizes a super-sampled sample buffer and a sample-to-pixel calculation unit for refreshing the display. The graphics system may have a graphics processor, a super-sampled sample buffer, and a sample-to-pixel calculation unit. The graphics processor renders samples into the sample buffer at computed positions or locations in the sample buffer. The graphics system may utilize a window ID that specifies attributes of pixels on a per object basis. The window ID may specify one or more of a sample mode, filter type, color attributes, or source attributes. The sample mode may include single sample per pixel mode and multiple samples per pixel mode. In implementing a single sample per pixel mode, the graphics system may be further operable to generate a single sample per pixel for certain windows of the screen in order to, for example, provide backwards compatibility with legacy systems with no multi-sampling support.

Abstract: A graphics system comprising a programmable sample buffer and a sample buffer interface. The sample buffer interface is configured to (a) buffer N streams of samples in N corresponding input buffers, wherein N is greater than or equal to two, (b) store N sets of context values corresponding to the N input buffers respectively, (c) terminate transfer of samples from a first of the input buffers to the programmable sample buffer, (d) selectively update a subset of state registers in the programmable sample buffer with context values corresponding to a next input buffer of the input buffers, (e) initiate transfer of samples from the next input buffer to the programmable sample buffer. The context values stored in the state registers of the programmable sample buffer determine the operation of an arithmetic logic unit internal to the programmable sample buffer on samples data.

Abstract: One embodiment of a method of frame detection may involve storing data indicative of a pulse duration and a number of successive occurrences of pulses having that pulse duration for each of several different pulse durations detected within a first field of a composite synchronization signal. This process may be repeated for one or more other fields of the composite synchronization signal. The data stored for each of the fields may be compared, and a frame signal may be generated dependent on an outcome of said comparing.

Abstract: In order to synchronize two dissimilar video formats, two or more phase locked loop circuits (PLL's) may be used in tandem. A first PLL circuit may be connected to the first video format (Master) and generate an intermediate frequency. A second PLL circuit may use the intermediate frequency as the timebase for generating the pixel clock for the second video format (Slave). One or more Slaves may be connected to the generated pixel clock. The video synchronizing device may be a part of a graphics system, such as a graphics accelerator.

Abstract: A graphic system may include a pixel synthesizing device that uses two or more phase-locked loops (PLL's) in tandem in order to achieve a better M/N ratio. The two PLL's connected in tandem have an effective M/N ratio of (M1*M2)/(N1*N2). The pixel synthesizing device is operable to synthesize free-running (non-genlocked, or sync-master) pixel clock frequencies using a much greater variety of M and N. As a result, greater precision in specification of the pixel clock frequency is achieved, yielding greater precision in a frame rate of a particular video format. As a result, the allowable channel spacing is greatly increased, and the graphic system can select from a wide range of ultradense spaced pixel clocks.

Abstract: A computer system may include several integrated circuits and a routing circuit configured to route several data streams between the integrated circuits. The routing circuit includes several input ports, several output ports, and a signature analysis register coupled to one of the output ports. The signature analysis register is configured to collect data conveyed via the output port dependent upon whether the signature analysis register receives a tag identifying one of the plurality of data streams.

Abstract: A system and method is disclosed for management of sample data to enable video rate anti-aliasing convolution. Sample data may be moved simultaneously from a sample buffer to a bin scanline cache and from the bin scanline cache to an array of N2 processor-memory units (e.g. 25 for N=5). Pixel data may be convolved from an N×N sample bin array that may be approximately centered on the pixel location. Since each sample bin contains Ns/b samples, Ns/b×N2 samples may be filtered for each pixel (e.g. 400 for N=5 and Ns/b=16). Each processor-memory unit convolves the sample data for one sample bin in the N×N sample bin array and supports a variety of filter functions. Pixel data may be output to a real time video data stream.

Abstract: A graphics system configured with a scheduling network, a sample buffer, a rendering engine and a filtering engine. The rendering engine is configured to generate samples in response to received graphics data, and to forward the samples to the scheduling network for storage in the sample buffer. The filtering engine is configured to send a request for samples to the scheduling network. The scheduling network is configured to compare a video set designation of the request to a previous request designation, to update one or more state registers in one or more memory devices of the sample buffer in response to a determination that the video set designation of the request is different from the previous request designation, and to assert signals inducing a transfer of a collection of samples corresponding to the request from the one or more memory devices to the filtering engine.

Abstract: A graphics system comprising a plurality of rendering pipelines and a scheduling network. Each rendering pipeline couples to the scheduling network, and includes a media processor, a rendering unit and a memory. A communication bus may couple the scheduling network and the memory of each rendering pipeline. The media processor in each rendering pipeline may direct the saving of state information of the corresponding rendering pipeline to the corresponding memory in response to receiving a corresponding context switch indication. A first of the media processors initiates the transfer of a resume token to the scheduling network through the corresponding rendering pipeline if the context switch occurs during an ordered processing mode. The scheduling network unblocks one or more rendering pipelines other than the first rendering pipeline in response to receiving the resume token.

Abstract: A graphics system that may be shared between multiple display channels includes a frame buffer, two arbiters, a pixel buffer, and several display output queues. The first arbiter arbitrates between the display channels' requests for display information from the frame buffer and forwards a selected request to the frame buffer. The frame buffer outputs display information in response to receiving the forwarded request, and pixels corresponding to this display information are stored in the pixel buffer. Each display channel has a corresponding display output queue that provides data to a display and generates a request for pixels from the pixel buffer. A pixel request arbiter receives the pixel requests generated by the display output queues, selects one of the pixel requests, and forwards the selected request to the pixel buffer. In response, the pixel buffer outputs pixels to the display output queue that generated the selected pixel request.

Abstract: A computer graphics system that utilizes a super-sampled sample buffer and a sample-to-pixel calculation unit for refreshing the display. The graphics system may have a graphics processor, a super-sampled sample buffer, and a sample-to-pixel calculation unit. The graphics processor renders samples into the sample buffer and may utilize a window ID that specifies attributes of pixels on a per object basis. The window ID may specify one or more of a sample mode, filter type, color attributes, or source attributes. The sample mode may include single sample per pixel mode and multiple samples per pixel mode. The graphics system may be further operable to generate a single sample per pixel for certain windows of the screen in order to provide backwards compatibility with legacy systems.

Abstract: A system and method are disclosed for reproducing a pre-selected larger 2-D sample location pattern from a smaller one by means of X,Y address permutation. This method, for example, allows hardware to effectively reproduce a pre-selected set of sample locations for an array of 128×128 sample bins from a smaller set of pre-selected sample locations for an array of 2×2 sample bins. A permutation logic unit may use a first portion of an address for a sample bin B to identify a corresponding 2-D transformation, apply the inverse of the transformation to a second portion of the sample bin address to identify the corresponding bin of the 2×2 array of sample bins, and apply the transformation to the sample locations stored in the corresponding bin to reproduce the sample locations pre-selected for sample bin B.