Abstract: A system, method, and a computer readable for inserting data into a cache memory based on information in a semi-synchronous memory copy instruction are disclosed. The method comprises determining a start of a semi-synchronous memory copy operation. The semi-synchronous memory copy operation is checked for a given value in at least one cache injection bit. In response to the given value in the cache injection bit, a predefined number of lines of destination data is copied into at least one level of cache memory.

Abstract: There is provided a method for routing packets on a linear of N processors connected in a nearest neighbor configuration. The method includes the step of, for each end processor of the array, connecting unused outputs to corresponding unused inputs. For each axis required to directly route a packet from a source to a destination processor, the following steps are performed. It is determined whether a result of directly sending a packet from an initial processor to a target processor is less than or greater than N/2 moves, respectively. The initial processor is the source processor in the first axis, and the target processor is the destination processor in the last axis. The packet is directly sent from the initial processor to the target processor, when the result is less than N/2 moves. The packet is indirectly sent so as to wrap around each end processor, when the result is greater than N/2 moves.

Abstract: A system, method, and computer program product for semi-synchronously copying data from a first portion of memory to a second portion of memory are disclosed. The method comprises receiving, in a processor, a call for a semi-synchronous memory copy operation. The semi-synchronous memory copy operation preserves temporal persistence of validity for a virtual source address corresponding to a source location in a memory and a virtual target address corresponding to a target location in the memory by setting a flag bit. The call includes at least the virtual source address, the virtual target address, and an indicator identifying a number of bytes to be copied. The memory copy operation is placed in a queue for execution by a memory controller. The queue is coupled to the memory controller. At least one subsequent instruction is continued to be executed as the subsequent instruction becomes available from an instruction pipeline.

Abstract: A system, method, and computer program product for semi-synchronously copying data from a first portion of memory to a second portion of memory are disclosed. The method comprises receiving, in a processor, a call for a semi-synchronous memory copy operation. The semi-synchronous memory copy operation preserves temporal persistence of validity for a virtual source address corresponding to a source location in a memory and a virtual target address corresponding to a target location in the memory by setting a flag bit. The call includes at least the virtual source address, the virtual target address, and an indicator identifying a number of bytes to be copied. The memory copy operation is placed in a queue for execution by a memory controller. The queue is coupled to the memory controller. At least one subsequent instruction is continued to be executed as the subsequent instruction becomes available from an instruction pipeline.

Abstract: Disclosed are a method, information processing system, and computer readable medium for managing interrupts. The method includes placing at least one physical processor of an information processing system in a simultaneous multi-threading mode. At least a first logical processor and a second logical processor associated with the at least one physical processor are partitioned. The first logical processor is assigned to manage interrupts and the second logical processor is assigned to dispatch runnable user threads.

Abstract: A method and system for efficient context switching are provided. An execution entity that is to be context switched out is allowed to continue executing for a predetermined period of time before being context switched out. During the predetermined period of time in which the execution entity continues to execute, the hardware or an operating system tracks and records its footprint such as the addresses and page and segment table entries and the like accessed by the continued execution. When the execution entity is being context switched back in, its page and segment table and cache states are reloaded for use in its immediate execution.

Abstract: There is provided a method for routing packets on a linear array of N processors connected in a nearest neighbor configuration. The method includes the step of, for each end processor of the array, connecting unused outputs to corresponding unused inputs. For each axis required to directly route a packet from a source to a destination processor, the following steps are performed. It is determined whether a result of directly sending a packet from an initial processor to a target processor is less than or greater than N/2 moves, respectively. The initial processor is the source processor in the first axis, and the target processor is the destination processor in the last axis. The packet is directly sent from the initial processor to the target processor, when the result is less than N/2 moves. The packet is indirectly sent so as to wrap around each end processor, when the result is greater than N/2 moves.

Abstract: A method and system for synchronizing allocation of resources in a parallel processing system. At predefined time intervals, each user application executing in a parallel processing system is given a higher priority such that the system resources are allocated to the user applications instead of the operating system services. This high priority lasts for a predetermined amount of time. When the time has elapsed, each priority value is lowered, thus giving the operating system services an opportunity to execute.

Abstract: Connections between the node switch sets associated with processors in large scalable processor arrays, such as those of the butterfly variety, are arranged, like the 2-D mesh array, in rows and columns between the node switch sets. Additional sets of switches called pivot switch sets are used to accomplish this. They are added to the processors and the processor switch sets to form processor clusters. The clusters are each assigned a logical row and column location in an array. Each pivot switch set is connected to all node switch sets in the same assigned column location and to all node switch sets in the same assigned row location as the pivot set. Consequently, any two node switch sets are connected by way of a pivot set located at either (a) the intersection row of the first node set and the column of the second node set or at (b) the intersection of the column of the first node set and the row of the second node set.

Abstract: A packet switch (25.sub.1) contains input port circuits (310) and output port circuits (380) inter-connected through two parallel paths: a multi-slot central queue (350) and a low latency by-pass cross-point switching matrix (360). The central queue has one slot dedicated to each output port to store a message portion ("chunk") destined for only that output port with the remaining slots being shared for all the output ports and dynamically allocated thereamong, as the need arises. Only those chunks which are contending for the same output port are stored in the central queue; otherwise, these chunks are routed to the appropriate output ports through the cross-point switching matrix. Each receiver classifies its resident chunks (as critical or non-critical) based upon both the urgency with which that chunk must be transmitted to its destination output port and by the status of the central queue. A critical chunk, i.e.

Abstract: A method and apparatus for transferring data between a main processor and its memory and a packet switch includes a first bus coupled to the main processor and its memory, a bidirectional first-in-first-out (FIFO) buffer coupled between the first bus and a second bus. The FIFO buffer having a first port connected to the first bus and a second port connected to the second bus. The apparatus further includes a communications processor, coupled to the second bus, a memory operatively coupled to the second bus, a first direct memory access (DMA) engine coupled between the first bus and the FIFO buffer for transferring data between the main processor and the FIFO buffer, a second direct memory access (DMA) engine coupled between the FIFO buffer and the second bus for transferring data between the FIFO buffer and the second bus, and a packet switch interface, operatively coupled between the second bus and the switch, for interfacing the second bus to the switch.

Abstract: A synchronous communication apparatus can be tuned to ensure reliable reception of signals propagating along transmission lines. The apparatus can be used as a communication port in a high frequency, highly connected synchronous network in which all ports can be tuned by a single, remote network control device. A local data source outputs a data signal during each of a series of local clock periods. A local source delay circuit receives input data signals from the local data source, and outputs output signals delayed by all amount (mT+.DELTA.pT) relative to corresponding input data signals, where m is a positive integer or zero, and where 0<.DELTA.p<1. The amount of the delay is dependent on the value of a source delay select signal. A local data receiver receives data signals from a local receiver delay circuit. The amount of delay of the local receiver delay circuit is also selectable.

Abstract: A communication system segment having phase multiplexing. A first communication station contains a data source which sequentially outputs a series of data signals during a series of clock periods. The data source outputs one data signal from the series during each clock period. The first communication station also contains a transition buffer which has an input connected to the output of the data source. The transition buffer has a first-in, first-out mode in which the transition buffer stores a series of Q data signals output from the data source during the most recent Q clock periods, where Q is an integer greater than zero. A second communication station contains a data receiver which sequentially inputs a series of data signals during a series of clock periods. The data receiver inputs one data signal from the series during each clock period. A communication line connects the output of the data source to the input of the data receiver.

Abstract: For use by a particular node within a digital data communications network having a plurality of counter-synchronized nodes including the particular node, called the central service node (CSN), and at least one remote node, all nodes being clocked at a common frequency, each node being synchronized by its own nodal time counter and connected to at least one other node by at least one transmission segment that completes a transmission path from the CSN, method and apparatus for: (a) establishing any value of virtual transmission delay (vtd) at individual transmission segments; (b) non-destructively determining the existing vtd at individual transmission segments; and (c) establishing basal distributions of vtd throughout the network and determining the elements thereof, (a), (b), and (c) being achieved without the central service node knowing real transmission delay (rtd) and inter-nodal asynchrony anywhere within the network and without requiring the active participation of any remote node.

Abstract: A communication network having a service processor, a plurality of terminal nodes, and a network of switch nodes for switchably connecting the service processor to each terminal node by way of one or more connection paths. Each switch node in the communication network is connected to the service processor either directly or through one or more other switch nodes. Each terminal node of the communication network is connected to a switch node. Each switch node and each terminal node has a device identification. At least two nodes have the same device identification. Each target node having the same device identification as another node can preferably be connected to the service processor by way of at least one connection path which does not include any other node having the same device identification as the target node. All switch nodes having the same minimum connection path length may, for example, have the same device identification.

Abstract: A simulation engine for logically simulating a logic network, which is divided into several levels of hierarchy. At the lowest level is a logic chip which has stored in an instruction memory a sequentially executed program of logical operators and operand addresses. The operand addresses refer to an input memory of the chip. The next highest level is the logic unit, on one circuit board, comprising a plurality of such logic chips. Each of the logic chips of the unit has its input memory receiving the same data from an input bus and a local bus and provides as its output one of the bits of an output bus and one of the bits of the local bus. At the next level, called a cluster, several logic units have their input and output buses interconnected by a plurality of switch units. All the logic chips of the several logic units operate in parallel with the exchange of data through the switch units. Several clusters can be combined into a super cluster by connecting together two or more sets of switch units.