Abstract: A massively-parallel computer includes a plurality of processing nodes and at least one control node interconnected by a network. The network faciliates the transfer of data among the processing nodes and of commands from the control node to the processing nodes. Each processing node includes an interface for transmitting data over, and receiving data and commands from, the network, at least one memory module for storing data, a node processor and an auxiliary processor. The node processor receives commands received by the interface and processes data in response thereto, in the process generating memory access requests for facilitating the retrieval of data from or storage of data in the memory module. The node processor further controlling the transfer of data over the network by the interface. The auxiliary processor is connected to the memory module and the node processor.

Abstract: When a processor within a computer system performs a synchronization operation, the system interface within the node delays subsequent transactions from the processor until outstanding coherency activity is completed. Therefore, the computer system may employ asynchronous operations. The synchronization operations may be used when needed to guarantee global completion of one or more prior asynchronous operations. In one embodiment, the synchronization operation is placed into a queue within the system interface. When the synchronization operation reaches the head of the queue, it may be initiated within the system interface. The system interface further includes a request agent comprising multiple control units, each of which may concurrently service coherency activity with respect to a different transaction. Furthermore, the system interface includes a synchronization control vector register which stores a bit for each control unit.

Abstract: The present invention provides a hybrid Non-Uniform Memory Architecture (NUMA) and Cache-Only Memory Architecture (COMA) caching architecture together with a cache-coherent protocol for a computer system having a plurality of sub-systems coupled to each other via a system interconnect. In one implementation, each sub-system includes at least one processor, a page-oriented COMA cache and a line-oriented hybrid NUMA/COMA cache. Such a hybrid system provides flexibility and efficiency in caching both large and small, and/or sparse and packed data structures. Each sub-system is able to independently store data in COMA mode or in NUMA mode. When caching in COMA mode, a sub-system allocates a page of memory space and then stores the data within the allocated page in its COMA cache. Depending on the implementation, while caching in COMA mode, the sub-system may also store the same data in its hybrid cache for faster access.

Abstract: A massively-parallel computer includes a plurality of processing nodes and at least one control node interconnected by a network. The network faciliates the transfer of data among the processing nodes and of commands from the control node to the processing nodes. Each each processing node includes an interface for transmitting data over, and receiving data and commands from, the network, at least one memory module for storing data, a node processor and an auxiliary processor. The node processor receives commands received by the interface and processes data in response thereto, in the process generating memory access requests for facilitating the retrieval of data from or storage of data in the memory module. The node processor further controlling the transfer of data over the network by the interface. The auxiliary processor is connected to the memory module and the node processor.

Abstract: Protocol agents involved in the performance of global coherency activity detect errors with respect to the activity being performed. The errors are logged by a computer system such that diagnostic software may be executed to determine the error detected and to trace the error to the erring software or hardware. In particular, information regarding the first error to be detected is logged. Subsequent errors may receive more or less logging depending upon programmable configuration values. Additionally, those errors which receive full logging may be programmably selected via error masks. The protocol agents each comprise multiple independent state machines which independently process requests. If the request which a particular state machine is processing results in an error, the particular state machine may enter a freeze state. Information regarding the request which is collected by the state machine may thereby be saved for later access.

Abstract: A programmable clock circuit generates a real time clock value, which is incremented in response to a real time clock increment signal. The real time clock increment signal is generated after a selected number of ticks of a system clock signal, with the number of ticks being determined by whether it is operating in a normal mode or an error compensation mode. In the normal mode, the real time clock increment signal is generated after a selected number of ticks of the system clock signal, which results in an increasing cumulative timing error. In the error compensation mode, the real time clock increment signal will be generated after a number of ticks of the system clock signal selected so as to reduce this cumulative error. The programmable clock circuit keeps track of the cumulative error in the real time clock signal while operating in the normal mode.

Abstract: A directory system directs cache line access requests from processors in a multi-processor system with a shared memory system through a cache line states directory. The cache line states directory stores a state value that identifies a cache line shared states word. The cache line shared states word identifies the processor that owns the cache line and the state of access of each processor that shares access to the cache line. A state value encoder encodes a cache line shared state word into a state value and loads the state value into the cache line states directory. A state value decoder decodes the state value into a cache line shared state word for use by the cache line directory system in retrieving the cache line. A plurality of cache line tables are used with each cache line assigned to one of the tables. The cache line table stores a state value for each cache line shared states word stored in the table.

Abstract: The present invention provides a hybrid Non-Uniform Memory Architecture (NUMA) and Cache-Only Memory Architecture (COMA) caching architecture together with a cache-coherent protocol for a computer system having a plurality of sub-systems coupled to each other via a system interconnect. In one implementation, each sub-system includes at least one processor, a page-oriented COMA cache and a line-oriented hybrid NUMA/COMA cache. Such a hybrid system provides flexibility and efficiency in caching both large and small, and/or sparse and packed data structures. Each sub-system is able to independently store data in COMA mode or in NUMA mode. When caching in COMA mode, a sub-system allocates a page of memory space and then stores the data within the allocated page in its COMA cache. Depending on the implementation, while caching in COMA mode, the sub-system may also store the same data in its hybrid cache for faster access.

Abstract: A computer comprising a plurality of processing nodes, a control node and a request distribution network. Each processing node receives processing requests and generates in response processed data. The control node generates processing requests for transfer to selected ones of the processing nodes as identified by associated request address information, and receives processed data in response, the request address information identifying selected ones of the processing nodes to receive a processing request in parallel. The request distribution network distributes the processing requests to the processing nodes and returns processed data to the control node. The network includes a plurality of request distribution nodes connected in a plurality of levels to form a tree-structure, including an upper root level and a lower leaf level.

Abstract: A digital computer includes a plurality of processing elements, a command processor, a diagnostic processor and a communications network. The processing elements each performs data processing and data communications operations in connection with commands. The processing elements also performing diagnostic operations in response to diagnostic operation requests and providing diagnostic results in response thereto. The command processor generates commands for the processing elements, and also performs diagnostic operations in response to diagnostic operation requests and providing diagnostic results in response thereto. The diagnostic processor generates diagnostic requests. The communication network includes three elements, including a data router, a control network and a diagnostic network. The data router is connected to the processing elements for facilitating the transfer of data among them during a data communications operation.

Abstract: A parallel computer comprising a plurality of processors and an interconnection network for transferring messages among the processors. At least one of the processors, as a source processor, generates messages, each including an address defining a path through the interconnection network from the source processor to one or more of the processors which are to receive the message as destination processors. The interconnection network establishes, in response to a message from the source processor, a path in accordance with the address from the source processor in a downstream direction to the destination processors thereby to facilitate transfer of the message to the destination processors. Each destination processor generates response indicia in response to a message. The interconnection network receives the response indicia from the destination processor(s) and generates, in response, consolidated response indicia which it transfers in an upstream direction to the source processor.

Abstract: In a random access memory, a dynamic memory array is associated with static data buffers. Each static data buffer is connected to the memory array to receive and store a row of data from any addressed row of the array. When an address is received, it is compared with addresses stored in registers and associated with the data stored in the static buffers. Where there is a match, a controller is able to select the data buffer in which the row of data is stored for a column strobe operation without the need for a row address strobe operation. The resultant system provides for a set associative cache coupled to the dynamic memory array. Further, the comparison can be made of virtual addresses for a cache system which responds to virtual addresses.