Apparatus for compressing data using a Lempel-Ziv-type algorithm

A data processing system having a compression and decompression apparatus based on the Lempel-Ziv algorithm. The compression apparatus includes an array section having a circular history CAM unit for receiving and storing one or more data elements and a coding unit for determining whether received data elements previously have been stored in the history CAM unit and are a candidate for compression. If a received data element matches at least one of the stored data elements, a PS logic section determines whether there is the presence of a string. An encoding section identifies the address of the matching stored data element in a string and the length of the string. The compression apparatus generates a compression token comprising an identification of whether a data element is compressed, the length of the coded data within a plurality of predetermined data length categories and an address. The compression apparatus uses a particular hardware implementation of the PS logic section.