DATA COMPRESSING DEVICE AND ITS METHOD

PROBLEM TO BE SOLVED: To obtain a device for achieving a high compression rate at a high speed by storing the processed segments of an input data stream in a history array having plural entries, and making a first-in first-out data buffer full or empty while the history array is searched. SOLUTION: Non-compressed bytes inputted from a line 244 are stored in an input FIFO 232, and transferred to FIFO registers 233 and 235. Data stored in the FIFO 233 are transferred through lines 248 and 250 to an FIFO register 235. The contents of the FIFO register 233 are outputted through lines 248 and 252, and the contents of the FIFO register 235 are outputted through lines 251 and 253 to a hash function 237, and transmitted through lines 237 and 255 to a multiplexer 256. When any matched string is not present in the contents of the FIFO register 233, compressed bytes are outputted from an output FIFO 234 to a line 270.