Abstract: A method and apparatus includes processing for restricting at least one video output of a computing system based on copy protection information. Such processing begins by receiving a video signal and associated copy protection information (e.g., Macrovision). The processing continues by interpreting the copy protection information. When the copy protection information indicates copy restriction, the processing continues by altering at least one video output. The video output may be altered by disabling a monitor output, adjusting a refresh rate to be incompatible with a television refresh rate, altering an image of the video signal, and/or inserting a message in a non-current interlaced field of the video signal.

Abstract: A method and apparatus for supporting multiple bus masters on an AGP bus is presented. A first bus master is configured as an AGP bus master and utilizes the AGP request portion of the AGP bus structure to issue bus master requests. A second bus master is configured as a PCI bus master and utilizes the PCI bus master request portion of the AGP bus to assert bus master requests. When bus master grants are received via the AGP bus, status lines are used to determine the character of the bus master grant. When the status lines indicate that the bus master grant is an AGP bus master grant, the AGP bus master performs AGP bus master operations. When the status lines indicate that the bus master grant is a PCI bus master grant, the PCI bus master is enabled and allowed to perform PCI bus mastering operations.

Abstract: The invention provides a method of providing commands to a command memory where a graphics processor will have commands available for execution as long as there are commands available. The command memory includes a first indicator to identify the command location most recently accessed by the graphics processor. A second indicator identifies the number of commands locations available to write commands based on the most recently accessed command location. As a result of the invention, the application processor only checks the availability of space to write commands after it has written enough commands to fill the command memory. On the graphics processor side, the command memory is never empty unless the graphics processor executes and consumes instructions faster than the instructions are written. It is also possible to associate a graphics mode with each address range. In this way, mode can be indicated without specifically sending mode information with each command.

Abstract: A method and apparatus for determining a byte select vector for a crossbar shifter include processing that begins by storing data in a first set of byte locations and in a second set of byte locations. Typically, a data operand is written into the first and a shift value is written into the second set of byte locations. The processing continues by obtaining a shift amount value for the data. The processing then continues by determining, for each byte multiplexor of a set of byte multiplexors associated with a corresponding output byte, whether a wrapped condition will occur based on the shift amount for the data. When the wrap condition occurs, a wrap shift amount is determined based on a mode of shifting. The processing then continues by generating a byte select vector for the set of byte multiplexors based on the wrap shift amount and the shift amount.

Abstract: In accordance with a specific embodiment of the present invention one of a first, second, and third reference signal generator is selected. When a first reference signal generator is selected, a value associated with the pulse width modulated register is compared to a second register to control generation of the reference clock. When a second reference signal generator is selected, a phase accumulator is used to generate the reference clock. When a third reference signal generator is selected, a digital phase locked loop generates the reference clock. The present invention is better understood with reference to specific embodiments.

Abstract: A method and apparatus for eliminating memory contention in a computation module is presented. The method includes, for a current operation being performed by a computation engine of the computation model, processing that begins by identifying one of a plurality of threads for which the current operation is being performed. The plurality of threads constitutes an application (e.g., geometric primitive applications, video graphic applications, drawing applications, etc.). The processing continues by identifying an operation code from a set of operation codes corresponding to the one of the plurality of threads. As such, the thread that has been identified for the current operation, one of its operation codes is being identified for the current operation. The processing then continues by determining a particular location of a particular one of a plurality of data flow memory devices based on the particular thread and the particular operation code for storing the result of the current operation.

Abstract: A method and apparatus for improving performance of an AGP device is provided. In one embodiment of the invention, a second-level cache is provided for a TLB, and part of the data or part of the address that is not otherwise used for determining a TLB entry is divided by a prime number to determine which TLB entry to allocate. One embodiment of the invention provides the ability to load multiple cache lines during a single memory access without incurring additional transfer, storage, or management complexities. The full number of bits of each memory access may be used to load cache lines. One embodiment of the invention loads multiple cache lines for translations of consecutive ranges of addresses. Since the translations included in the multiple cache lines cover consecutive ranges of addresses, the relationship between the multiple cache lines loaded for a single memory access is understood, and additional complexity for cache management is avoided.

Abstract: An adaptive speaker compensation system and method, such as for use in a multimedia computer, stores speaker response filter coefficients for each speaker and adaptively compensates received audio for non-linear speaker characteristics based on the stored speaker response filter coefficients. The speaker response filter coefficients preferably represent an inverse response of a speaker response curve for each speaker in the audio system. Preferably a library memory containing prestored speaker characteristic data, such as the speaker response filter coefficients, is selectively accessed by the adaptive speaker compensation system to download the speaker response filter coefficients based on identification of a speaker type and channel for which the speaker is being used.

Abstract: In a specific embodiment, a system for providing video includes a system bus, which in one embodiment is an Advanced Graphics Port (AGP) busy. The system bus is connected to a data bridge, which is connected to a second and third AGP bus. Each of the AGP busses are connected to graphics processors. The bridge routes data requests from one graphics processor to the second graphics processor without accessing the system AGP bus based upon a memory mapping information stored in a routing table or a register set. In another aspect of the present invention, the bridge responds to initialization requests using attributes that may vary depending on the specific mode of operation. Another aspect of the present invention allows for conversion between various AGP protocol portions.

Abstract: A method of writing information to a synchronous memory device by examining a present word of N bits to be written, where each bit has a high or low value. The present word is compared to a previous word also having N bits to identify the number of bit transitions from a low value to a high value or vice versa. The present bit is inverted when the number of transitions is greater than N/2. To avoid the need for having an extra bit accompany data bytes to indicate the presence or absence of inversion, the method takes advantage of a data mask pin that is normally unused during writing operations to carry the inversion bit. Non-inverted data is written directly into the memory device while inverted data is first inverted again before writing to storage locations, so that true data is stored in the memory device.

Abstract: The method provides for sort independent alpha blending of fragments of a graphic image. A sequence of fragments has opaque fragments and transparent fragments. The opaque fragments are rendered to a frame buffer having at least a z buffer, the z buffer having stored therein z values of front most opaque fragments. Transparent fragments are stored in a list in a transparent fragment buffer. The transparent fragments are sequentially read from the list and are discarded if they are occluded by an opaque fragment. When not occluded, the transparent fragments are stored in a list. The z buffer is cleared and the transparent fragments are read sequentially from the list. Z values are stored in the z buffer for back most transparent fragments. The transparent fragments are again sequentially read from the list. Z values of currently read transparent fragments are compared to z values in the z buffer of corresponding fragments.

Abstract: An object to be displayed on a display screen is converted into at least one graphic primitive having associated texture data. The texture data is analyzed to determine whether operations associated with the texture data are commutative. A processor or a display engine is selected for performing the texture data operations based on in part the analysis.

Abstract: A digital communication receiver includes a blind equalizer using the Constant Modulus Algorithm (CMA) to compensate for channel transmission distortion in digital communication systems. Improved CMA performance is obtained by using a partial trellis decoder to predict 1 bit or 2 bits of the corresponding 3-bit transmitted symbol. The predicted bits from the partial trellis decoder are used to reduce the effective number of symbols in the source alphabet, which reduces steady state jitter of the CMA algorithm. Specifically, the received input signal to the CMA error calculation is shifted up or down by a computed delta (&Dgr;), in accordance with the predicted bit(s). In addition, a different constant gamma (&ggr;), for the CMA error calculation is selected in accordance with the predicted bit(s).

Abstract: An integrated circuit receiver includes a differential input receiver having a plurality of differential input transistors. A variable well voltage supply circuit varies the well voltages of the differential input transistors to change the input transistors threshold voltages to provide hysteresis control by varying well voltages of input transistors in opposite directions. A method for reducing noise for an integrated circuit receiver includes receiving an input signal by a differential input receiver, and changing into opposite directions the input transistors threshold voltages to provide hysteresis control by varying the first and second well voltages associated with each of a first differential input transistor and a second differential input transistor. At least one feedback signal is used from the differential input receiver as input to the variable well voltage supply circuit to vary the first and second well voltages to facilitate hysteresis control of the differential input receiver.

Abstract: An apparatus for processing a non-planar graphics primitive employs an associated method of operation and includes a controller, at least one computation engine, memory and at least one lookup table. Responsive to operation codes issued by the controller, the computation engine(s) determines a group of control points based on the position coordinates and normal vectors of the non-planar primitive vertices. The computation engine(s) then determines position coordinates of supplemental vertices defining multiple planar tessellated primitives based on the control points and stored weighting factors that provide a cubic relation between the control points and the position coordinates of the supplemental vertices. A first memory stores at least the control points and at least one lookup table stores the cubic weighting factors.

Abstract: In a specific embodiment, a system for providing video is disclosed, the system having a system bus, which in one embodiment is an Advanced Graphics Port (AGP) bus. The system bus is connected to a data bridge, which is connected to a second and third AGP bus. Each of the AGP busses are connected to graphics processors. The bridge routes data requests from one graphics processor to the second graphics processor without accessing the system AGP bus based upon a memory mapping information stored in a routing table or a register set. In another aspect of the present invention, the bridge responds to initialization requests using attributes that may vary depending on the specific mode of operation. Another aspect of the present invention allows for conversion between various AGP protocol portions.

Abstract: A method and apparatus for utilizing a data cache in a system with both 2D and 3D graphics applications. In a specific embodiment of the present invention, a mode signal is received by the video system indicating whether a 2D or 3D application is to be used. Depending on the mode signal, either as a unified cache capable of being accessed by two separate data access streams, or two independent caches, each accessed by one data access stream.

Abstract: An apparatus and method dynamically controls the graphics and/or video memory power dynamically during idle periods of the memory interface during active system modes. In one embodiment, a memory request detector generates memory request indication data, such as data representing whether memory requests have been received within a predetermined time, based on detection of graphics and/or video memory requests during an active mode of the display system operation. A dynamic activity based memory power controller analyzes the memory request indication data and controls the power consumption of the graphics and/or video memory based on whether memory requests are detected.

Abstract: A method and apparatus for utilizing mip maps in a video graphics system begins by setting a dynamically configurable level of detail bias that is used to select between potential mip maps. The level of detail bias is set based on the screen resolution. The selection of the mip map, or mip maps, utilized for texturing operations with respect to a particular pixel is performed based on the configurable level of detail bias and the texel-per-pixel ratio between the potential mip maps and the particular pixel to be textured. The dynamic configuration of the level of detail bias allows texture detail to be maintained across multiple display resolutions.

Abstract: An instruction aligner and method evaluates a fixed length instruction cache line by breaking it into at least two components. These two components, in one embodiment, include half of the instruction cache line being designated as most significant bytes and the second half of the instruction cache line being designated as least significant bytes. A byte right rotator is responsible for feeding the next sixteen bytes of the instruction stream, while a byte right shifter shifts the unused bytes of the current sixteen bytes the aligner is working on. The byte rotator and byte shifter combine to provide aligned variable length instructions for decoding based on either a fetch PC value or current instruction length.