International Business Machines Corporation

James William Feeney

Howard Thomas Olnowich

George William Wilhelm, Jr

Robert Francis Lusch

John David Jabusch

Jehoshua Bruck

Michael Hans Fisher

Michael W Dotson

Michael Anthony Maniguet

Eli Upfal

Edward Stanley Suffern

Raymond J Eberhard

Eliezer Upfal

Arthur Robert Williams

Robert William Bartoldus

Jorge R Rodriquez

A method for conserving energy in a computing unit and transferring data between the computing unit and an external source. The computing unit is in a power saving mode. The method includes receiving at the computing unit a request from an external source, determining which components of the computing unit are required to respond to the request, selectively activating, from the power saving mode, the components of the computing unit necessary to respond the request, and responding to the request using the selectively activated components of the computing unit. As one example, the computing unit may comprise a laptop, and the external source may comprise a PDA, and the request may include a request from the PDA to retrieve data from or store data on the laptop.

Low power access to a computing unit from an external source

A method and system for adjusting a message preamble on a shared bus, wherein the message preamble includes N synchronization characters, and each of the synchronization characters is separated in time by a random delay interval. First, an activity status is determined for the shared bus in terms of the number of stations that are currently active on the bus. The number of synchronization characters is then adjusted according to the bus activity status. The activity status is also utilized as a dynamic adjustment parameter for the random delay interval that includes a fixed delay term, D, added to a randomly determined delay increment, d. In this manner the message preamble specification is optimized according to real-time network demands, such that latency and data collisions are minimized.

Dynamic preamble configuration on a shared bus

A communications apparatus is provided comprising a plurality of FIFO buffers, each with independent control and priority logic under software control for supporting different types of message traffic, both send and receive, such as comprise a multimedia server system. Processor software directs messages to specific, optimized FIFO buffers. Further, a system is provided including a plurality of nodes wherein a sending node specifies the communications path through the system, selecting specific FIFO buffers in each node for buffering its messages.

Multi-tasking adapter for parallel network applications

An apparatus that converts and adapts standard processor bus protocol and architecture, such as the MicroChannel bus, to more progressive switch interconnection protocol and architecture. Existing bus-based architecture is extended to perform parallel and clustering functions by enabling the interconnection of thousands of processors. The apparatus is relatively easy to implement and inexpensive to build. The communication media is switch-based and is fully parallel, supporting nodes interconnected by the switching network.

Apparatus for coupling a bus-based architecture to a switch network

Disclosed is is a switch-based network interconnection which uses intelligent switching apparatus devices for improving the performance and connection establishing capability of multi-stage switching networks. The invention method is particularly effective In asynchronous circuit-switched networks. The most important feature of the invention methodology is the an increasing probability for the success of making a connection through all the stages of a multi-satge network. As a connection progresses through a multi-stage network, it must win successive stages of the network, one at a time, until it has made its way from on side of the network to the other and established the commanded source-to-destination connection. The uniqueness in the present invention is that as the connection at each stage of the network is established, looking forward to the next stage, the probability will be greater of establishing the next connection without encountering blocking than it was for the present stage. This presents an ever increasing probability for establishing a successful connection as a path works its way through the network. This is opposite of most traditional networks, whose probabiltiy for success diminishes with every stage in the connection sequence.

Increasing probability multi-stage network

A method and apparatus for reducing the software overhead of message passing in parallel systems. Special purpose hardware assists in constructing each data message sent through a network. Message passing systems generally require that every message be prefixed with a message header describing the key control parameters of the message. The software task is to construct the message header for every message individually and to transmit the header prefixed to every message. The software is relieved of constructing the message header and uses special purpose hardware to accomplish the job more efficiently.

Automatic hardware message header generator

A digital parallel processing system wherein a plurality of nodes communicate via messages sent over an interconnection network. Messages are maintained in strict chronological order even though sent by nodes where several sources are generating messages simultaneously. A network adapter is described for interconnecting the processor and its associated memory to a network over a bus. The adapter includes an adapter associated memory programmable into a plurality of functional areas, said functional areas including a send FIFO for storing and forwarding messages to said network from said processor; a stack list for queueing in strict message order activation commands for said send FIFO; and an adapter program area for storing adapter program instructions which control the storing of messages to said send FIFO; and control means responsive to said stack list for executing said adapter program instructions in said strict message order without processor intervention.

Method and apparatus for maintaining message order in multi-user FIFO

The present invention addresses the limitations of prior art ALLNODE switches by including dual priority, adaptive, path seeking, and flash-flood functionalities in a single ALLNODE switch. The switch of the present invention further includes a selection device responsive to a selection signal for enabling the selection of the mode of switch operation from any one of the foregoing functionalities. The selection signal is applied to the switch in a number of different ways including: the transmission of a command over the data path interface to the switch; the transmission of a command over special purpose serial or parallel control lines; or via hardwiring. Thus, the selection of functionality for the switch is capable of being made in either a dynamic or static fashion. The present invention further comprises two new high performance networks utilizing the selectable function ALLNODE switch. The networks have a different functionality being performed at each stage, and comprise a 'Multi-Dilated Path Seeking Network' and a 'Nested Path Seeking and Flash-Flood Network.'

Multi-stage interconnection network with selectable function switching

A method and hardware apparatus provide a fault tolerant and flexible multi-stage network addressing scheme for transmitting a message with a header containing control bits for selecting from various destination checking functions to be performed. Upon arrival of the message at a node, destination checking is performed or not in response to the massage's header. If destination checking is not performed, or if destination checking is performed and indicates that the node is the desired destination for the message, the message is accepted. If destination checking is performed and indicates that the node is not the desired destination for the message, the message is rejected. Destination checking is disabled during address assignment, broadcasting and multi-casting, and replaced with one's complement-based verification of the sending node.

Selectable checking of message destinations in a switched parallel

A conversion apparatus that converts and adapts standard processor bus protocol and architecture, such as the MicroChannel (IBM Trademark) bus, to more progressive switch interconnection protocol and architecture. Existing bus-based architecture is extended to perform parallel and clustering functions by enabling the interconnection of thousands of processors. A conversion apparatus controls the transfer of data messages from one nodal element across a switch network to another nodal element by using direct memory access capabilities controlled by intelligent bus masters. This approach does not require interactive support from the processor at either nodal element during the message transmission, and frees up both processors to perform other tasks. The communication media is switch-based and is fully parallel, supporting n transmissions simultaneously, where n is the number of nodes interconnected by the switching network.

Apparatus for adapting message protocols for a switch network and a bus

A data processing system gives an application running on the operating system exclusive ownership of a hardware device. The system is operable in two modes. In the first mode the application interacts with the hardware device by making use of the processing system. In this mode many layers of the processing system are involved and the interaction time with the hardware is slow and inconsistent. In the second mode, exclusive ownership of the hardware device is granted to the application by the driver. In this mode the application has direct access to the hardware device thus avoiding the involvement of the processing system layers. The application accesses and uses the driver through a low latency processor interface linked into the application program itself.

System having device driver operates in first mode for allowing

An electronic switching and data transmission system for interconnecting a plurality of buses. A switching network interconnects several multi-drop buses using adapters to connect the buses to the switching network. The adapters implements hardware functions to appear to software as if all devices on the several buses were attached to a single large bus. The system permits higher speed transfer modes by eliminating multi-drop bus limitations.

Switch network extension of bus architecture

A multi-stage circuit switched network for improving connection establishment using intelligent switching devices. As a transmission makes its way through the network stages, the probability of connecting to a destination increases, i.e., the chance of encountering a blocked device output is decreased. This is opposite of most traditional networks, whose probability for success diminishes with every stage in the connection sequence.

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Endicott, NY, United States of America

James William Feeney