Showing papers on "Routing (electronic design automation) published in 1971"

Wire routing by optimizing channel assignment within large apertures

Abstract: The purpose of this paper is to introduce a new wire routing method for two layer printed circuit boards. This technique has been developed at the University of Illinois Center for Advanced Computation and has been programmed in ALGOL for a B5500 computer. The routing method is based on the newly developed channel assignment algorithm and requires many via holes. The primary goals of the method are short execution time and high wireability. Actual design specifications for ILLIAC IV Control Unit boards have been used to test the feasibility of the routing technique. Tests have shown that this algorithm is very fast and can handle large boards.

Minimum cost routing for dynamic network models

Abstract: This paper develops techniques which can be applied to long range planning studies for the domestic long haul communications network. The problem studied is how to select a path through the network for each point-to-point demand for communications channels, so that the total network cost is minimized. The problem is to minimize total network cost, subject to multicommodity flow requirements and concave link cost functions. Finding an exact solution is difficult because of the concavity of the cost functions and the complexity (100 to 200 nodes and 200 to 300 links) of the network structure. A specialized technique is developed to provide locally optimal solutions to the problem, one of minimizing a concave function over a convex constraint set. When the link cost displays a fixed charge, a modification of the iterative algorithm provides acceptable a modification of the iterative algorithm provides acceptable solutions. Even though the global optimum cannot be found amidst the immense number of local optima, several sample problems demonstrate the value of the techniques developed. A companion paper will extend this work to the dynamic routing problem, of deciding how to route future demands and install transmission facilities so as to minimize the present worth of expenditures during the study interval. The methods and goals of these modeling efforts will be discussed in the companion paper.

Template for use in the routing of workpieces

Abstract: A routing template comprises a body adapted to overlie a workpiece to be routed and having an opening formed in the body for the accommodation of a routing tool. Atop the body is carried a plate having a predetermined thickness and having an opening therein of an area corresponding to the area of the workpiece to be routed, the area of the opening in the plate being no greater than that of the opening in the body and communicating with the latter. The plate may be replaced by any one of a number of other plates of different thickness and having openings of different sizes so as to vary the depth and area of the cut made in a workpiece. The body is provided with means for clamping and unclamping the body to the workpiece to be routed.

Multifunction routing network

Abstract: A multifunction routing network. The routing network is provided with a function control means including a condition responsive logic network having an iterative multifunction control loop. Register and memory means are also provided in the routing network which are operatively associated with the control means for providing input conditions thereto and for receiving output conditions therefrom. The logic network is provided with a multistable means having a plurality of states and is responsive to the states thereof and the input conditions thereto to provide a plurality of control functions of both a data control and an execute non-data control nature for the routing network. A computer, an input keyboard, an audio-visual playback device, and a television are also provided which are operatively associated with the register and memory means for providing input conditions thereto and for responding to output conditions therefrom.

Connection Routing Algorithm for Printed Circuit Boards

Abstract: A generalized algorithm for forming interconnections between points on a multilayer circuit board is described and evaluated. The algorithm treats interconnections on individual layers and connections between layers by means of plated holes. Generalizing the well-known Lee algorithm and using its terminology, this algorithm makes use of a coded C array that is stored in memory and records the state of the multilayer circuit board. Completed paths, possible remaining paths between points to be connected, and circuitboard interconnection restrictions are recorded in the coded C array. The algorithm consists of five iterative steps that involve decisions on the basis of the state of the circuit board as stored in the C array. All possible routes are attempted, and the routing sequence is stopped when the path is completed or all attempted path routes are exhausted. A number of modifications to the algorithm permitting various circuit connection constraints to be satisfied are also presented. The algorithm has been programmed for a GE-635 computer. Typical results for some of the printed circuit boards that were used to evaluate the algorithm are included.

Card routing apparatus

Abstract: Cards are transported by reversible transporting means between an input station, a readout and recording station, and a printing station. Routing means are disposed between the input station, and the readout and recording station, for discharging returned cards, and other routing means are located between the readout and recording station, and the printing station, for discharging read out cards which need not reach the printing station. The routing means cooperate with reversible transporting means for the cards.

Polarised plug-in adaptor - designed esp. for telephone equipment and easily assembled with printed cct.

Abstract: The adaptor contains a printed circuit board with input and output contacts perpendicular to each other. The input fits e.g. the printed circuit board in telephone routing equipment. Components can be soldered as required to the circuit board. The whole is enclosed in an insulating housing which is preferably a snap fit onto the board, and is so shaped that the plug fits in only one orientation. Further improvements to the housing include a locking screw, and grips formed in the sides. By installing the contacts on the same side as the circuit board with a plug-in direction set 90 deg. off enough space is created for the fitting of the components.

Telephone line transfer circuit using disjoint routing network for partial decoding

Abstract: An intercom telephone system having a relay counter which includes a disjoint routing contact network. For single digit codes, the routing network decodes ringing applied to a first input thereof onto one of 10 outputs depending on the digit dialled. For two digit codes, a transfer circuit connected to one of the 10 outputs is activated by a transfer signal applied to the first input after the first digit, to switch the ringing source to a second input of the routing network. After the second digit is dialled, ringing applied to the second input is partially decoded by the routing network onto one of four of the outputs. The remaining decoding onto one of 10 further outputs for two digit stations is effected by two relays in the transfer circuit slaved to two corresponding relays in the relay counter. Thus, a portion of the routing network is reused on the second digit of two digit calls for partial decoding.

Apparatus for routing recesses in doors and the like

Abstract: An apparatus for accurately and concurrently routing recesses in both doors and associated door jambs to receive hinges of different sizes. The apparatus automatically follows a templet device which can be readily adjusted to form recesses for different size hinges.

CIBOL - an interactive graphics program used in the design of printed wiring boards and generation of associated artmasters

Abstract: CIBOL (CIrcuit BOard Layout) is an application program that uses a computer graphics facility to aid in the design of low density discrete component printed wiring boards. There are three distinct program phases: creating the board outline, positioning the components, and routing the interconnections. A light pen and scope display are used interactively during the three program phases. The program directly generates manufacturing information on auxiliary peripherals in the form of parts lists, component layouts, drilling lists and artmasters. The use of the program has resulted in considerable savings in the cost of producing printed wiring board designs and reduction in the turnaround time from design inception to completion.

System for Heuristic and Rapid Processing of Component Layout and Wiring (SHARPCLAW)

Abstract: A computer-aided design system for layout of printed wiring boards is described, with emphasis on component placement and conductor routing algorithms. The system is designed to operate with a data base; placement and routing may be accomplished automatically using force field techniques and a maze-following procedure, or manually with extensive error checking by the computer. Examples of the system output are given.