DATA COMPRESSION STORAGE ARITHMETIC UNIT

PROBLEM TO BE SOLVED: To reduce the capacity of data occupying a storage device, to reduce the transfer quantity of data between a storage device and a computing element and to improve the processing speed of a computer by compressing data, storing the compressed data in the storage device and expanding the compressed data to use them for operation. SOLUTION: A data compressing circuit 5 and an expanding circuit 6 are connected between the computing element 1 and a bus control circuit 4 for writing an operation result in the storage device 9 to compress the operation result and expand data inputted from the storage device 9. The compressed data are stored in a physical address 8 converted form logical address 7 found out buy an address generator 2 through a paging control circuit 3 and the information of a compressing method is stored in a paging table in a paging conversion process. At the time of referring to the compressed data form the storage device 9, expanding processing is executed based on the information stored in the page table and operation is executed by the computing element 1.