Abstract: A digital interface device is provided for facilitating key encryption of a digital signal which is communicated from a computer system to an associated peripheral device, such as a digital display device. The digital interface device has a digital output, digital output formatting circuitry associated with the output and a non-volatile RAM for storing a basic input/output system (BIOS) for, inter alia, controlling digital output formatting. The interface device is configured such that the non-volatile RAM has a specific addressable write-protectable area allocated for storing an encryption key flag at a flag address along with encryption key data. The write-protectable area is rendered read-only when a predetermined flag value is stored at the flag address.

Abstract: A computer system has at least one processor and at least one queue for storing instructions for execution by the processor. The processor is capable of being clocked at a plurality of rates. A number of instructions in the queue is measured. The optimum clock rate is selected based on in part the determined number of queued instructions.

Abstract: A method and apparatus for supporting multiple displays per a drawing surface begins by receiving capability parameters regarding a first display of the multiple displays. The capability parameters include resolution, pixel depth, and/or refresh rate. Typically, the first display will be the primary display associated with a video graphics card. The processing continues by substituting selected display capabilities for the capability parameters of the first display. The selected display parameters are such that it exceeds the display capability parameters of each display, or monitor, coupled to the video graphics card. The processing continues by providing the selected display capabilities to an operating system. The operating system then stores the selected display capabilities in the display register associated with a particular video graphics card.

Abstract: In accordance with the invention, a video source is received by a first video adapter. The video source is captured in the video memory associated with the first VGA. The stored video source is associated with a window of an existing application. When the window location of the existing application is shifted to coincide with the video memory of a second graphics adapter, a data transfer occurs to the appropriate video memory location of the second graphics adapter to allow the rendering of that portion of the video now residing on a second monitor.

Abstract: A method and apparatus for performing tessellation lighting operations for video graphics primitives in a video graphics system is presented. When the vertex parameters corresponding to the vertices of a video graphics primitive are received, a tessellation operation is performed such that a number of component primitives are generated. The vertex parameters corresponding to the vertices of the component primitives are then calculated utilizing the vertex parameters for the original video graphics primitive. Such calculation operations include determining a corresponding normal vector for each component primitive vertex. Each of the component primitives is then individually processed. Such processing may include calculating the lighting effects for each component primitive and performing additional processing operations that generate pixel fragments for the primitive.

Abstract: Profiling execution of a program. The program is coded in a mode-dependent instruction set. During a profile-quiescent execution interval, the profile circuitry records no profile information. After a triggering event is detected, the profile circuitry commences a profiled execution interval, and records profile information describing every profileable event during that interval. The profiled information includes at least all divergence of execution from sequential execution and processor mode changes not inferable from instruction opcode. The recorded profile information is efficiently tailored to annotate the profiled binary code with sufficient processor mode information to resolve mode-dependency, and indicates contiguous ranges of sequential instructions executed during a profiled interval by low and high boundaries of the contiguous ranges, indicating the high boundary by the address of the last byte.

Abstract: A copy protection (CP) key used by a sending source, such as a POD, to encrypt content such as audio and/or video information is derived by a first key generator associated with a first processor and is locally encrypted by the first processor using a locally generated bus encryption key to produce a bus encrypted CP key that is sent over a local unsecure bus to a second processor, such as a graphics processor. The second processor decrypts the bus encrypted copy key using a decryption engine to obtain the CP key. The second processor receives the encrypted content and in one embodiment, also uses the same decryption engine to decrypt the encrypted content. The first and second processors locally exchange public keys to each locally derive a bus encryption key used to encrypt the CP key before it is sent over the unsecure bus and decrypt the encrypted CP key after it is sent over the bus.

Abstract: A system for traversing and rendering a graphic primitive, comprising a setup engine that outputs representative values of a graphic primitive; and a raster engine that receives the representative values of the graphic primitive and forms therefrom representative pixels, the raster engine having at least a scan module that scans only pixels within the graphic primitive and assigns data values to each of the pixels and a look-ahead module that identifies pixels that are inside of the primitive.

Abstract: A method and apparatus utilizes a three dimensional rendering engine to rotate an image based on user selected or otherwise determined screen orientation. A vertex coordinate transformation is defined for a rotated destination image. The source image is used as a texture for texture mapping during rendering operation to produce rotated image. In one embodiment, a separate set of software instructions is used for each orientation mode. Accordingly, a non-pixel by pixel based 3D rotation may be carried out using a 3D rendering engine to avoid a single parameter based seriatim pixel by pixel based orientation.

Abstract: A method and a computer with circuitry configured for performance of the method are disclosed. During a profiled interval of an execution of a program on a computer, profile information is recorded describing the execution, without the program having been compiled for profiled execution. The program is coded in an instruction set in which an interpretation of an instruction depends on a processor mode not expressed in the binary representation of the instruction. The recorded profile information describes at least all events occurring during the profiled execution interval of the two classes: (1) a divergence of execution from sequential execution; and (2) a processor mode change that is not inferable from the opcode of the instruction that induces the processor mode change taken together with a processor mode before the mode change instruction. The profile information further identifies each distinct physical page of instruction text executed during the execution interval.

Abstract: An input/output circuit in a receiving mode typically has disabled output buffers as well as other electrical components that provide significant receiver input capacities at high operating frequencies. A detection circuit detects the charging/discharging of the parasitic capacitance and operates a regulating circuit to compensate for the charging/discharging of the parasitic capacitance during rising/falling edges of an input signal, thereby correcting for impedance mismatch and reflection glitches.

Abstract: A configurable bus interface circuit includes an internal bus bridge and an internal circuit. The configurable bus interface circuit also includes an internal I/O circuit couplable to an external circuit, via the internal bus bridge. The configurable bus interface circuit electrically isolates the internal circuit to avoid the propagation of signals between the internal I/O circuit and the external circuit.

Abstract: In accordance with the specific embodiment of the present invention, a tuner alternates between receiving a first video signal and a second video signal, such that every other frame of a specific signal is received. This is accomplished by writing to an IF1 and IF2 control register, during a vertical blanking interval. Subsequently, the video images are displayed in full motion video by interpolating the alternating frames of data not received by the tuner.

Abstract: A computer concurrently executes a first operating system coded in a RISC instruction set and a second operating system coded in a CISC instruction set. When an exception is raised while executing a program coded in the RISC instruction set, an execution thread may be initiated under the CISC operating system. The exception may be delivered to the initiated thread for handling by the CISC operating system.

Abstract: A method and apparatus for gamma correction in a video graphics circuit is accomplished by storing a plurality of gamma correction curves in one or more lookup tables that can be accessed using pixel display information to generate gamma-corrected data. Gamma correction selection information is provided to select which of the gamma correction curves is utilized to perform the gamma correction for a particular set of pixel data.

Abstract: A wireless drawing command transmitting unit includes a wireless transmitter operative to transmit drawing commands associated with a master image renderer. A wireless drawing command receiving unit includes a wireless receiver operative to receive the transmitted drawing commands and generates an image for a display device using the drawing commands transmitted wirelessly. In addition, the wireless drawing command receiving unit transmits drawing command throttle data back to the wireless drawing command transmitting unit to throttle transmission of drawing commands that are sent by the drawing command transmitting unit. A method for providing wireless display of images is also disclosed.

Abstract: A graphics processor receives a compressed encrypted video stream. The graphics processor decrypts the compressed encrypted video stream and stores a decrypted version (i.e., a decrypted compressed video stream) in a protected portion of an on-chip or off-chip video memory. The graphics processor then permits processors and other bus masters on the graphics processor to access the on-chip video memory, but conditionally limits access to other bus masters that are located off-chip, such as a central processing unit located off-chip and coupled to the graphics processor via a bus.

Abstract: A method and apparatus for multiplexing data streams is provided. An earliest time and a latest time are determined for each packet of a each data stream. The packets of the data streams are multiplexed so as to meet earliest time and latest time requirements. The calculation of the earliest time and the latest time are simplified by allowing use of linear constraints rather than irregular stairstep constraints. Compensation for drift in the data streams is also provided.

Abstract: A computer is disclosed. The computer has a general register file of registers, a RISC instruction decoder, and a CISC instruction decoder. The RISC instruction decoder is exposed for execution of user-state programs in a RISC instruction set, being an instruction set having fixed-length instructions and a load/store/operate organization. The hardware CISC instruction decoder is exposed for execution by user-state programs in a CISC instruction set, being an instruction set with variable-length instructions and many instructions having multiple side-effects. The CISC decoder is designed to decode a portion of an instruction set for the computer, and to deliver the decoded instructions to an instruction execution pipeline designed to execute the output of both the RISC instruction decoder and the CISC instruction decoder. A software emulator is programmed to implement a remainder of the instruction set.

Abstract: A signal phase shifting circuit shifts the phase of an input signal, such as a STROBE signal, based on a reference signal, such as a CLOCK signal, to facilitate, for example, receiving of double data rate data. The signal phase shifting circuit includes a reference signal period dividing circuit having a feedback delay matching array operatively coupled to one of a plurality of voltage control delay lines. This signal phase shifting circuit also includes a variable delay circuit that provides a phase shifted output signal, such as a phase shifted STROBE signal, that includes a delay stage in a phase shifted output signal drive buffer coupled to the delay stage, such as a voltage control delay line. The feedback delay matching array includes a plurality of serially coupled buffer stages operatively coupled to compensate for delay variations associated with the phase shifted output signal drive buffer in the variable delay circuit.