Showing papers on "Routing (electronic design automation) published in 1973"

The design of store-and-forward (s/f) networks for computer communications

Abstract: : The emphasis of this research is on the development of mathematical programming tools for the design of S/F communication networks. An analytical model for the system is first presented and discussed. The design variables (routing of messages, channel capacities, topology, etc.) are then defined and proper design criteria (delay, cost, thruput, etc.) are established and expressed in terms of the variables. Next, various design problems are defined and investigated; the most significant of them here follow: (1) Find the minimum cost channel capacity assignment, given the routing of the messages and the maximum admissible delay T; (2) Find the routing which minimizes the delay, given the channel capacities (and therefore the cost); (3) Find the routing and capacities assignment which minimizes the cost, given the maximum admissible delay T. (4) Find the topology, routing and capacities assignment which minimizes the cost, given the maximum admissible delay T. (Author Modified Abstract)

How Big Should a Printed Circuit Board Be

Abstract: This correspondence outlines a theory for choosing printed circuit board dimensions in order to avoid crowding of printed wiring. Given a number of components to be mounted on the board and the dimensions of wiring, the theory predicts a minimum board size that should be easy to lay out. The theory does not tell how many components should be put on a board.

Computer controlled optical sort system

Abstract: A material unit, such as a vehicle for supporting luggage and articles of similar configuration, is guided around a track layout from a check-in station to a remote distribution station by a central computer in communication with an array of local station computers. Mounted on the material unit is a light reflective vehicle identification bar code that is optically read as the unit moves around the track layout. A unit destination code is input to the central computer that also receives the vehicle identification code from the optical reader and compiles a routing sequence that is communicated to selected ones of the local station computers. As the material unit approaches a local station, an optical reader responds to the bar code and an identification signal is transmitted to the local station computer for comparison with the routing sequence. The material unit is either diverted to a selected remote distribution station or allowed to pass to the next local station in accordance with the comparison sequence. Throughout the movement of the material unit around the track layout, the central computer, in conjunction with the local station computers, monitors the material unit for guidance to the selected destination. The central computer also maintains each material unit in an en route routine to insure that the location of each material unit is known at all times and to provide a warning indication when a unit fails to reach its destination and is lost.

Sliding three dimensional packaging technique

Abstract: Apparatus incorporating a novel three-dimensional systems packaging technique facilitating the implementation of direct electrical interconnections between a plurality of printed circuit cards thereby eliminating the routing of electrical signal paths to the card edges. The apparatus basically comprises a plurality of connector cards having contact means mounted thereon for establishing electrical connections directly therethrough. As the printed circuit cards are interleaved between the connector cards, the contacts slide on a track correspondingly disposed on the circuit cards. After insertion, the circuit cards are displaced, e.g., downward, so that the contacts slide from the tracks onto corresponding circuit access points disposed adjacent to the tracks, establishing an electrical connection between the adjacent circuit cards. Platedthrough holes are also provided to interconnect circuit access points on opposite sides of the circuit card.

Routing and conveying apparatus

Abstract: A device of the conveyor type for moving sheets of material, the device being of the type having an entry location and a plurality of output stations and comprising means for routing one or more of said sheets into a selected one of the output stations, said output stations being positioned along the sides of the device. If desired, a secondary device for separating sheets of material running two or more abreast is provided.

Computer-aided topological design for integrated circuits

Abstract: Component placement and wire routing are looked at as a coupled surface layering problem on two planes. This problem is transformed into a graph theoretic synthesis problem by neglecting the lateral dimensions of components and wiring. A solution is given by programmable algorithms.

A router for multilayer printed wiring backplanes

Abstract: Multilayer printed wiring backplanes cause a special problem for design automation. The very size of the problem tends to make routing techniques which are satisfactory for smaller boards prohibitively expensive for larger ones. At the same time, however, the following factors make it mandatory that adequate computer routing exist.1. The number of connections to make, the number of layers available and the ability to use vias makes the problem too complex for manual routing.2. Backplanes generally come late in system design and thus become critical path items.3. Backplanes are subject to design changes and sometimes require massive rework on short schedules.There are a number of routing techniques used today on smaller problems. The most common of these are the maze (Lee's)1 method and the ray (Hightower)2 method.In this paper, we will discuss alternate routing technique, designed around the special features of backplanes and multilayer boards. Examples will be given to show that this technique is faster (more than two orders of magnitude over a maze type) than maze or rays ones.

On a multinet wiring problem

Abstract: A multinet wiring problem is proposed. This problem has application in the routing of interconnection wires on integrated circuit chips and printed circuit boards. Optimal and suboptimal algorithms, based on the branch-and-bound method, are described for its solution.

New topological method for laying out printed circuits

Abstract: Topological methods of designing printed and integrated circuits have recently been the subject of much interest. A new algorithm is now presented for the construction of the graph of a circuit. Not only does this algorithm produce simpler graphs than it was possible to produce by the use of earlier methods, but it also retains much of the freedom normally associated with manual routing. Using this algorithm, conductors can be rerouted automatically if they lie in the path of another conductor, and certain options are left open as long as possible to minimise the probability of failure. There is no restriction on routing conductors among the terminals of a component. The experience gained with the algorithm so far is encouraging.

Algorithm 456: routing problem

Abstract: L.D. Fosdick and A.K. Cline, Editors Submittal of an algorithm for consideration for publication in Communications of the ACM implies unrestricted use of the algorithm within a computer is permissible. Copyright @ 1973, Association for Computing Machinery, Inc. General permission to republish, but not for profit, all or part of this material is granted provided that ACM's copyright notice is given and that reference is made to the publication, to its date of issue, and to the fact that reprinting privileges were granted by permission of the Association for Computing Machinery.

New topological method for laying out printed circuits

Abstract: Topological methods of designing printed and integrated circuits have recently been the subject of much interest. A new algorithm is now presented for the construction of the graph of a circuit. Not only does this algorithm produce simpler graphs than it was possible to produce by the use of earlier methods, but it also retains much of the freedom normally associated with manual routing. Using this algorithm, conductors can be rerouted automatically if they lie in the path of another conductor, and certain options are left open as long as possible to minimise the probability of failure. There is no restriction on routing conductors among the terminals of a component. The experience gained with the algorithm so far is encouraging.

A new current-routing logic counter

Abstract: The integrated synchronous 2 3 -counter described below uses binary current-routing logic stages with a minimum number of components, crossings and collector islands Maximum toggle frequency is 60 MHz at 12 mW per stage With few interconnections between identical chips a synchronous 2 9 -counter can be realized

Response routing in selcuk networks and lashley's dilemma

Abstract: Given a large net of modules of limited logic and memory in which connectivity is primarily to near neighbors with one-way channels, the question is asked of how responses to a generally broadcast request can be routed to the site of the request. A routing procedure which does not require site information is proposed. The procedure is based on the Selcuk Principle which maintains that in properly constructed networks routing can be achieved with each module remembering only on which input channels the request had first arrived. The procedure is successfully applied to a neural network model proposed by Eccles and to one advanced by Burns. The strongest requirement of the proposed procedure is that there be switching among output channels and this appears consistent with the findings of Chun, Raymond & Lettvin (1970) that there is selective invasion of axonal arborization. Since the Selcuk Network scheme achieves response routing on the basis of strictly local information, pursuant to the broadcast of a general message, it has applicability to content-based addressing and to computer-to-computer communication nets. It also constitutes an approach to pattern recognition whereby the image on the “retina” is transformed into a time spectrum of responses, the analysis of which yields information on angle, size, curvature, and position of the edges.

On Optimal Routing Through Communication Nets

Abstract: This paper describes a procedure for a suboptimal routing of simultaneous multiterminal multicommodity flows in circuit switched communication networks. The procedure is based on a concept of topological importance of a branch in a capacitated net with a given structure and relative to a given pattern of communication requirements. Once these importance weights have been attached to the branches of the net, the problem reduces to finding in a weighted network the shortest path between two nodes. The chosen objective here is to optimize the grade of service (GS) by satisfying (on a long-range traffic policy basis) the changing "call" demands presented to the network, as fully as possible.

System for adjusting and commutating current in the windings of an AC machine from a constant-voltage DC supply

Abstract: System enabling an AC machine to have the characteristics of a DC machine. The system comprises a chopper (T10), a smoothing choke (L1), a thyristorized routing bridge for switching the current in the motor M (T1 to T6), two turn-off circuits (C1, T7, T''7, T8, T''8), two switching circuits (C2, C3) and two circuits for discharging the capacitors (C2, C3) (one in association with (T9) and the other in association with (L3). A diode bridge (D11 to D16) is interposed between, on the one hand, the routing bridge, and, on the other hand, the turn-off and switching circuits. The system is of use for speed controllers and traction motors.

Computer Algorithm for Routing Oversized Trucks

Abstract: A computer algorithm for routing oversized trucks through a network was developed. The basic input to the algorithm consists of the usual network description in terms of speed and distance on constituent links, and in addition, the height and weight limits on each link, and the height and weight of the truck to be routed between specified origins and destinations. The algorithm computes the minimum time path on the basic network or on the residual network subsequent to removal of all links having an allowable height and weight less than the corresponding parameters for the truck to be routed. The output also includes the distance along the minimum time path and the corresponding overweight fee computed on the basis of a certain rate per excess ton-mile traveled. These outputs can then be compared to determine the increase in user costs resulting from routing a truck over a minimum time path that avoids restricted links.

GRAFOS - A symbolic routing language

Abstract: Interactive computer aids for integrated circuit layout usually offer a choice between slow, high-precision plotters or fast, low-resolution interactive media. A system, called GRAFOS, has been designed, which attempts to overcome resolution limitations by the use of symbolic referencing. It employs a symbolic routing language through which both the electrical connectivity and the geometry of the circuit interconnections are specified. This paper presents the syntax and symbology of the GRAFOS language, together with examples illustrating its adaptability to a variety of routing styles, e.g. slant lines, custom layout, polycell routing. Also included is a brief description of the GRAFOS operating system.

Multicommodity Throughput in Digital Data Networks with Finite Storage

Abstract: A model of a digital data message switching network is described. The network permits only finite storage at nodes. Discussed is a routing strategy and storage allocation to maximize throughput between many source-receiver pairs simultaneously.