Abstract: A microprocessor system is disclosed having a high speed system bus for coupling system elements, and having a dual bus microprocessor with separate ultra-high speed instruction and data cache-MMU interfaces coupled to independently operable instruction and data cache-MMU, respectively. A main memory is coupled to the system bus for selectively storing and outputting digital information. The instruction and data cache-MMU's are coupled to the main memory via the system bus for independently storing and outputting digital information to respective mapped addressable very high speed cache memory. The microprocessor is coupled via separate and independent very high speed instruction and data buses to each of the instruction cache-MMU and data cache-MMU, respectively, for processing data received from the data cache-MMU responsive to instructions received from the instruction cache-MMU.

Abstract: A cache and memory management system architecture and associated protocol is disclosed. The cache and memory management system is comprised of a set associative memory cache subsystem, a set associative translation logic memory subsystem, hardwired page translation, selectable access mode logic, and selectively enableable instruction prefetch logic. The cache and memory management system includes a system interface for coupling to a systems bus to which a main memory is coupled, and is also comprised of a processor/cache bus interface for coupling to an external CPU. As disclosed, the cache memory management system can function as either an instruction cache with instruction prefetch capability, and on-chip program counter capabilities, and as a data cache memory management system which has an address register for receiving addresses from the CPU, to initiate a transfer of defined numbers of words of data commencing at the transmitted address.

Abstract: A microprocessor architecture is disclosed having separate very high speed instruction and data interface circuitry for coupling via respective separate very high speed instruction and data interface buses to respective external instruction cache and data cache circuitry. The microprocessor is comprised of an instruction interface, a data interface, and an execution unit. The instruction interface controls communications with the external instruction cache and couples the instructions from the instruction cache to the microprocessor at very high speed. The data interface controls communications with the external data cache and communicates data bidirectionally at very high speed between the data cache and the microprocessor. The execution unit selectively processes the data received via the data interface from the data cache responsive to the execution unit decoding and executing a respective one of the instructions received via the instruction interface from the instruction cache.

Abstract: In a cache memory system, multiple-word boundary registers, multiple-word line registers, and a multiple-word boundary detector system provide accelerated access of data contained within the cache memory within the multiple-word boundaries, and provides for effective prefetch of sequentially ascending locations of stored data from the cache memory. In an illustrated embodiment, the cache memory stores four words per addressable line of cache storage, and accordingly quad-word boundary registers determine boundary limits on quad-words, quad-word line registers store, in parallel, a selected line from the cache memory, and a quad-word boundary detector system determines when to prefetch the next set of quad-words from the cache memory for storage in the quad-word line registers.