MEMORY INTERFACE COMPRESSION

摘要

Data storage within a memory is performed on a block-by-block basis. A block of memory locations is allocated within the memory. In some embodiments the block size does not depend upon the degree of compression of individual blocks and is at least as large as required for the uncompressed data thereby simplifying memory management and access. A block of data values to be stored within the memory can be compressed to form a compressed block of data values. This compressed block of data values normally has a storage capacity requirement smaller than the storage capacity of the allocated block of memory locations. This leaves an unused portion of the allocated block of memory locations. When the block of data values stored in an allocated block of memory locations is modified, then a modified compressed block of data values is formed and this can be accommodated within the originally allocated block of memory locations by utilising some of the unused portion. Whether compression is used or the particular compression scheme used may vary on a block-by-block basis, such as in dependence upon whether compression processing actually reduces size, the device generating or consuming the data concerned, the data stream identity or in some other way. The blocks of memory storage locations may be matched in size to the size of a buffer store within the memory. Control codes, such as an end-of-block code or an exception code, may be stored with the compressed blocks to control their processing.