Abstract: A sequential process-pipeline has a first processing stage (30) coupled to a CODEC (24) through a plurality of buffers, including an image data input buffer (28), an image data output buffer (26), and an address buffer (34). The image data input buffer stores, for each block of image data, control information for controlling the processing of an associated block of image data. The address buffer stores addresses, each of which identifies an initial address of a block of addresses within an image memory (22). A local controller (18) is responsive to the writing of an address into the address buffer to read the control information for a block to be processed, and to initiate the operation of the CODEC, in accordance with the read-out information, to execute a Discrete Cosine Transformation Process and a Discrete Cosine Transformation Quantization Process.

Abstract: A sequential process-pipeline (12) has a first processing stage (30) coupled to a CODEC (24) through a plurality of buffers, including an image data input buffer (28), an image data output buffer (26), and an address buffer (34). The address buffer stores addresses, each of which identifies an initial address of a block of addresses within an image memory (22). Each block of addresses in the image memory stores a block of decompressed image data. A local controller (18) is responsive to the writing of an address into the address buffer to initiate the operation of the CODEC to execute a Discrete Cosine Transformation Process and a Discrete Cosine Transformation Quantization Process.

Abstract: A hierarchical memory system for use with a high speed data processor characterized by having separate dedicated cache memories for storing data and instructions and further characterized by each cache having a unique cache directory containing a plurality of control bits for assisting line replacement within the individual cache memories and for eliminating many accesses to main memory and to insure that unnecessary or incorrect data is never stored back into said main memory.The present cache architecture and control features render broadcasting between the data cache and instruction cache unnecessary. Modification of the instruction cache is not permitted. Accordingly, control bits indicating a modification in the cache directory for the instruction cache are not necessary and similarly it is never necessary to store instruction cache lines back into main memory since their modification is not permitted.