Abstract: A method and apparatus for flexibly filtering upstream scheduling messages in a communication system is described. The inventive method and apparatus uses software to rapidly filter a MAP message comprising a plurality of information elements. In accordance with the inventive method, a communication device inputs a MAP message and outputs a filtered MAP message comprising upstream transmission information relevant only to the communication device. The communication device stores data relevant to its upstream transmit opportunities. This data is derived from information elements that are associated with the communication device. In one embodiment, the communication device stores a transmit time. In another embodiment, the communication device stores a transmit time and a transmit duration. In yet another embodiment, the communication device stores a transmit time, a transmit duration and an IUC.

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: An interrupt driven interface coupling a programmable media access controller (MAC) and a process controller. The interrupt driven interface is operable within a cable modem system. The specification by which the cable modem operates to transfer data between the programmable media access controller (MAC) and the control processor is loaded into a memory location within the system, and the physical system is operable to provide for backward compatibility, in that, the addition of new messages and the deletion of old messages within the specification is performed via software upgrade. The necessity of a re-design and re-fabrication of the programmable media access controller (MAC) and the control processor, and the interface between them is completely obviated by the present invention.

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.