In a multiprocessory system comprising a plurality of CPUs interconnected by a common bus, means are provided whereby the CPUs are periodically and cyclically enabled to access the bus. Data transfer from one CPU to another is performed by first storing the data into a main memory connected to the bus, then transferring the data from main memory to the destination CPU when the latter is enabled to utilize the bus and is in a condition to accept the data. Means can also be provided whereby, when ...

An input/output system for a processor of the kind in which a processor module has a central processing unit, a memory, an input/output channel, and a plurality of device controllers for controlling the transfer of data between the processor module and the peripheral devices includes a star poll connection in which each device controller is provided with a signalling means for signalling its identity in response to a poll operation, independently of other similarly connected device controllers s...

A multiprocessor system used, for example, in a personal computer, wherein different types of microprocessors are used independently of the architecture of each microprocessor. The system includes a control register, a control circuit, and a common peripheral circuit mounted, for example, on a main board, and a plurality of kinds of microprocessors each mounted, for example, on a sub-board connected to the main board. The control circuit transmits a halt request signal to a first microprocessor ...

In this invention, when a service processor must request processing to all of n processors, it supplies a processing request to one of the n processors using a 1:1 inter-processor communication instruction. The processor receiving the request from the service processor then supplies a processing request to the remaining (n-1) processors using a 1:n inter-processor communication instruction. A bus control unit for controlling a system bus has a flag indicating whether or not the 1:1 (or 1:n) inte...

A splittable/connectible bus 140 and a network 1000 for transmitting coherence transactions between CPUs are provided between the CPUs, and a directory 160 and a group setup register 170 for storing bus-splitting information are provided in a directory control circuit 150 that controls cache invalidation. The bus is dynamically set to a split or connected state to fit a particular execution form of a job, and the directory control circuit uses the directory in order to manage all inter-CPU coher...

A multiprocessor system can reduce a broadcast for cache memory consistency control with memory access from an I/O device. The multiprocessor system is provided with a cache memory identifier or an owner tag, and a block length table for recording a memory write block length of the I/O device. The cache memory identifier records that the cache has an exclusive copy. The owner tag records that there is no cache memory having an exclusive copy. If there is an exclusive copy during read through the...

A cache status report sum up for use in a multiprocessor system having a plurality of processor units each having a processor and a cache memory and a plurality of memory units. The cache status report sum up apparatus sums up cache coherency check results indicating statuses of the cache memories without limiting the number of memory access requests requiring cache coherency checks that can be overlapped when the memory access requests requiring cache coherency checks are executed in an overlap...

A server blade is provided with an enclosure. The server blade can be provided with a plurality of processors in the enclosure. The server blade can be configured as a field replaceable unit removably receivable in a carrier of a modular computer system, for example a high density blade server system. The enclosure for such a multiprocessor server blade can be larger that a standard enclosure for a single processor server blade. The carrier can be configured to receive such an oversized server b...

A multiprocessor array with a first shadow register unit (3) which operates within a first clock domain, at least one second shadow register unit (11) which operates within a second clock domain, and a peripheral unit (17) which operates within a peripheral clock domain. Within all clock domains there are provided register units (3, 11, 20) which have a construction that is functionally identical.

A multiprocessor information handling system that can absorb a load imbalance without increasing a size of a data buffer.