Lockheed Martin Corporation

Unisys Corporation

Steven Allen Murphy

Donald B Bennett

Brian Ralph Larson

Rick C Stevens

John A Krawczak

David P Andersen

Michael E Farmer

Multi-stage switching networks may be constructed and expanded from small to very large networks that are contained within a compact physical volume. This is accomplished by replication of a pre-selected network module containing switches by a rotating, folding and squaring process that substantially reduces the length of connections between switches. This geometry allows very large networks by inductively combining smaller networks into larger networks. In networks constructed with this geometry, the length of the longest connections between switches is proportional to the square root of the number of ports provided by the network.

Implementation of multi-stage switching networks

An expandable network constructed from a plurality of identical network fabric cards which uses a plurality of selected row address bits to route connection paths between adjacent columns of interconnecting switches and a software algorithm for implementing a network of any whole number power of 2 rows or ports by assigning numbers of the network switches and attached nodes are described.

Single-type fabric card networks and method of implementing same

The Scalable Coherent Interface (SCI) standard of the Institute of Electrical and Electronics Engineers is intended for fast, high throughput, point-to-point, unidirectional links. It is to serve high-performance multiprocessor systems. A number of key elements are defined as part of the protocol for SCI. These include: (a) command.old which is a bit in transmitted packets for detecting stale packets to discard; (b) idle.cc which is an idle bit to be inserted between packets for detecting lost packets which toggles when the idle bit has circulated around the ringlet; and (c) idle.ac which is an idle bit which toggles when all operational nodes have had an opportunity to transmit. In addition, SCI contemplates the implementation of a number of different types of resets, including power reset, upon read or apparent loss of power for more than a second and linc reset for clearing circuits but not changing error count registers in the system. An implementation of SCI for a switching network which does not contain full agent switches (i.e., switches that have queues), as contemplated by SCI is disclosed which extends the utilization of the above-noted key elements. This implementation provides for a substantial reduction in the complexity, size, power and costs of the network. The network may be expandable in that it can service more than the current number of required operational rings which have at least one scrubber node and may have one or more other functional nodes therein, while handling misrouted packets by providing recirculation conductive connections to all input and output ports of the network that are not connected to such operational rings.

Initialization of switching networks for use with a scalable coherent

The Scalable Coherent Interface (SCI) standard of the Institute of Electrical and Electronics Engineers is intended for fast, high throughput, point-to-point, unidirectional links to high-performance multiprocessor systems. A system is provided for routing packets with a plurality of data bits and target identity code bits through a packet routing switching network. The packets are transmitted from source nodes through the switching network to target nodes that are designated by the target identity code bits. Operational rings are used to link output ports of switches of the output stages to input ports of switches of the input stage wherein each operational ring is identified by ring identity code bits associated with the input stage switches of the operational rings and has at least one node which is capable of performing a function with the data. Recirculation rings are used to link output ports of switches of the output stage to input ports of switches of the input stage. The recirculation rings have no functional nodes in them. Each output port of the output stage switches is coupled to either an operational ring or to a recirculation ring, and the packets are transmitted from source nodes through the operational rings. In the event any of said packets are misrouted, then the packets are transmitted through the recirculation rings or through the operating rings that do not contain the designated target nodes until the packets reach their respective designated target nodes.

Recirculation routes in switching networks used with scalable coherent

A multi-node Scalable Coherent Interface ring for the transmission of packets between nodes, each of which contains an SCI link controller to which a B-link controller that contains a timer is coupled and a gigabit transceiver to which a G-link controller that contains a timer is coupled, is provided. The SCI link controller, the B-link controller and the G-link controller are utilized to allow the SCI link controller and the transceivers to be initialized and synchronized in a manner such that these devices may be utilized in a multi-node SCI packet network.

Multi-node interconnect topology with nodes containing SCI link

The Scalable Coherent Interface (SCI) standard of the Institute of Electrical and Electronics Engineers is intended for fast, high throughput, unidirectional links to high-performance multiprocessor systems. Key elements of the protocol for SCI include: (a) a 'new/stale' bit which is generated in a data packet for detecting stale packets to discard; (b) an idle.cc which is an idle bit to be inserted between packets for detecting lost packets which toggles when the idle bit has circulated around the ringlet; and (c) a scrubber node in each operational ring of an SCI network which toggles 'new/stale' bits from a 'new' state to a stale state when they are received at the scrubber node. The 'new/stale' bit is also set to a 'new' stale bit when a packet is generated in a source node in a first operational ring for transmission to a target node in a second operational ring. A scrubber node is located as the first node of each operational ring of the network. The new/stale' bit and the idle circulation (idle.cc) is used to keep track of misrouted and lost packets. Each of a plurality of switches of the switching network is assigned to one of a plurality of rows of the switches and to one of a plurality of stages of the switches. Each of the switches has a plurality of input ports and output ports associated therewith. Input ports are coupled to the switches of the input stage, and output ports equal in number to the number of input ports are coupled to the switches of the output stage. The number of switches in a row is equal in number to the number of stages of the switching network. The packets are transmitted from the input ports to the output ports through operational rings that are connected thereto until each of the packets reaches a designated target node.

Detection of lost packets in switching networks used with scalable

A deadlock avoidance system for avoiding interconnection deadlocks between a plurality of data transfer devices includes a controller, a switch interconnector coupled to all of said data transfer devices for interconnecting on a one-to-one basis selected ones of the data transfer device as requesting units to selected ones of said data transfer devices as receiving units. A transfer queue is employed that includes a master transfer register and a slave transfer register, a master register, a slave register and a target register.

Deadlock avoidance for switched interconnect bus systems

A radar pulse detection and classification system receives times-of-arrival of pulses from simultaneous emitters over a wide range of pulse repetition frequencies (PRF's). The pulses are deinterleaved into bands of pulse repetition intervals (PRI's) so that a fixed number of pulses are required for detection of an emitter regardless of the PRI of the emitter. The pulse periodicities of the pulses in a pulse stream are determined by autocorrelation, and candidate emitter PRI's are selected from the pulse periodicities which were determined by autocorrelation. The pulses of candidate emitters are time-integrated to obtain time-integrated signals, and emitters are detected from peaks in the time-integrated signals. The time-continuity of said pulses are measured to determine emitter existence. The system receives pulses from both jittered and non-jittered emitters. It estimates jitter width in a pulse stream by utilizing peak pulse widths found by autocorrelation and removes jittered emitters from a pulse stream by predicting their times of arrival from the known PRI phase and jitter estimated for a previous pulse stream.

Radar pulse detection and classification system

A Layered Network system may provide varying cost from order NlogN low-cost networds, to completely-routing, fully-Layered networks with cots of order Nlog .sup.3 N. Layered networks are composed of switches and point-to-point connections between them. These networks establish connections from requestors to responders by relaying 'requests' through the switches. Each switch has built-in control logic to route requests and responses. The switch setting is determined using the comparison of the request with the request's current location in the network, and with locally competing requests. To provide distributed routing without a centralized controller, each switch routes the requests using only the information contained in the requests that switch handles. The switch setting is remembered in order to route the responses on the same paths as the associated requests, but in the reverse direction.

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Apple Valley, MN, United States of America

Steven Allen Murphy