1. A parallel pattern detection engine (PPDE) integrated circuit (IC) for detecting one or more patterns in a sequence of input data comprising: an input/output (I/O) interface for coupling data into and out of the PPDE; M processing units (PUs), each of the M PUs having compare circuitry for comparing each of the sequence of input data to a pattern stored in each of the M PUs and generating a compare output, wherein an address pointer selecting the pattern in each of the M PUs is modified in response to a logic state of the compare output and an operation code stored with the pattern; an input bus for coupling the sequence of input data to each of the M PUs in parallel; an output bus coupled to the I/O interface for sending output data to the I/O interface; control circuitry coupled to the I/O interface and coupling control data on a control data bus and identification (ID) on an ID bus to each of the M processing units; ID selection circuitry for selecting a match ID from ID data identifying the M PUs in response to a pattern match signal and match mode data, wherein the match ID and match data corresponding to the match ID are saved in a temporary register as the output data; and cascade circuitry coupled from each of the M PUs to one or more adjacent PUs within the M PUs for selectively coupling chain data between one or more groups of two or more adjacent PUs selected from the M PUs in response to the control data.