Abstract: A raster to block converter and equivalently a block to raster converter can be implemented using enough memory to contain a single image band, that is a band of pixels of height equal to a single block but spanning the entire width of an image. The raster to block converter can operate at full rate so that as soon as a pixel is read out from the memory a new pixel can be stored in its place. The location of a pixel can be tracked using a mapping involving basic modular arithmetic. This raster to block converter is scalable so that it can work with any size image and block size.

Abstract: A raster to block converter and equivalently a block to raster converter can be implemented using enough memory to contain a single image band, that is a band of pixels of height equal to a single block but spanning the entire width of an image. The raster to block converter can operate at full rate so that as soon as a pixel is read out from the memory a new pixel can be stored in its place. The location of a pixel can be tracked using a mapping involving basic modular arithmetic. This raster to block converter is scalable so that it can work with any size image and block size.

Abstract: A communication device such as a cable modem that has a first interface for receiving data from a cable media, and a pattern matching engine that evaluates patterns in the data that is received at the first interface of the cable modem and that enables the determination of appropriate procedures for treatment of the data. The pattern matching engine of the cable modem may be configured to match address segments of the data that is received at the first interface of the cable modem. In addition, the pattern matching engine is often a programmable pattern matching engine that may be programmed according to patterns that are desired to matched during various operations of the cable modem. Of note, the pattern matching engine enables pattern matching of various length frame portions. Various aspects of the present invention may also be found in a method for a communication device to compare a predetermined pattern to a pattern that corresponds to a portion of a data frame.

Abstract: A cable modem having a programmable media access controller (MAC). A single cable modem device includes all necessary MAC functions. The invention allows programmable MAC functions to support evolving standards (e.g., DOCSIS) without requiring expensive hardware upgrades. Bifurcated microprocessor architecture, in which first processing circuitry is programmed to implement MAC functionality for processing information flowing to and from cable media interface circuitry, and second embedded processor core or host system processor provides operating system functionality are used. Alternatively, separate processor cores provide MAC functionality for downstream and upstream data paths, respectively. Cable media interface circuitry, and other peripheral circuitry, are coupled to a peripheral bus that is linked by a bridge circuit to a system bus. The processing circuitry MAC is communicatively coupled to the system bus.

Abstract: A method for detecting dropouts in digital data transferred over a bus from a digital data source to a computer system. Each address in the computer system buffer memory is initialized to a selected code value known not to exist in the data to be transferred. After sequential transfer of data to the buffer memory, the presence of the selected code value in the buffer memory indicates that a dropout occured.

Abstract: A communication device, such as a cable modem, having a programmable media access controller (MAC) supported by a programmable CRC engine. The CRC engine computes CRC values for data written to it by the programmable MAC or other software process, thereby relieving processing circuitry of these computationally burdensome functions. The programmable nature of the CRC engine permits compliance with a wide variety standards, including evolving standards such as DOCSIS, without requiring expensive hardware upgrades. In one embodiment of the invention, the CRC engine may be initialized by the programmable MAC with an initial vector prior to CRC computations. The programmable MAC or other software then locates the data bytes (e.g., data frame header data) for which a CRC is to be computed. This information is written to a data register of the CRC engine and a CRC operation is performed. Based on the results, the programmable MAC may determine whether the CRC operation indicates valid data.

Abstract: A cable modem having a programmable media access controller (MAC). A single cable modem device includes all necessary MAC functions. The invention allows programmable MAC functions to support evolving standards (e.g., DOCSIS) without requiring expensive hardware upgrades. Bifurcated microprocessor architecture, in which first processing circuitry is programmed to implement MAC functionality for processing information flowing to and from cable media interface circuitry, and second embedded processor core or host system processor provides operating system functionality are used. Alternatively, separate processor cores provide MAC functionality for downstream and upstream data paths, respectively. Cable media interface circuitry, and other peripheral circuitry, are coupled to a peripheral bus that is linked by a bridge circuit to a system bus. The processing circuitry MAC is communicatively coupled to the system bus.

Abstract: A method and apparatus for processing digital stereo signals in a stereo system having a left and right channel in which digital information corresponding to the left and right channels is read from a source of digital information. The left and right channels of information are duplicated and various duplicated signals are processed by predetermined functions. The duplicated signals are manipulated by a plurality of user-defined functions to form a space signal, which is combined with other signals to form left and right output signals.

Abstract: Programmable apparatus for digital processing of video signals from multiple sources converted to digital format to provide real-time multiple simultaneous special video effects and suitable for direct interface to a conventional microcomputer bus such as an Apple Macintosh II NuBus. The apparatus includes a matrix of multipliers to do real-time video processing permitting special effects such as fading between at least two video image sources, as well as a priority resolver to control display on a pixel by pixel basis of more than ten sources based upon dynamically programmable priority. In addition, a programmable multiple range thresholder, a hardware window generator capable of generating multiple simultaneous windows, a color look up table and optional image capture capabilities are provided. The apparatus also provides for a light pen input, genlocking and a range of special video effects including zooming, mosaicing, panning and blending.