Abstract: Global address and data routers interconnect individual system units each having its own processors, memory, and I/O. A domain filter coupled to the routers dynamically defines groups of system units as domains and clusters of domains which have both software and hardware isolation from each other. Clusters can share dynamically definable ranges of memory with each other. The domain filter has software-loadable registers on the system units and in the global routers to set the parameters of the domains and clusters. The registers label individual inter-system transactions on the routers as invalid for system units not in the same domain or cluster as the originating unit.

Abstract: A direct-execution microprogrammable microprocessor system uses an emulatory microprogrammable microprocessor for direct execution of microinstructions in main memory through a microinstruction port. A microinstruction cache with a microinstruction address extension unit serving to communicate microinstructions from the main memory to the microprogrammable microprocessor. Virtual main memory accesses occur through a system multiplexer. A virtual address extension unit and a virtual address bus provide extension and redefinition of the main memory address space of the microprogrammable microprocessor. The system also uses a context switching stack cache and an expanded address translation cache with the microprogrammable microprocessor having a reduced and redefined microinstruction set with a variable microinstruction cycle.

Abstract: Global address and data routers interconnect individual system units each having its own processors, memory, and I/O. A domain filter coupled to the routers dynamically defines groups of system units as domains and clusters of domains which have both software and hardware isolation from each other. Clusters can share dynamically definable ranges of memory with each other. The domain filter has software-loadable registers on the system units and in the global routers to set the parameters of the domains and clusters. The registers label individual inter-system transactions on the routers as invalid for system units not in the same domain or cluster as the originating unit.