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Mechanism for Wiring Logic

IP.com Disclosure Number: IPCOM000045209D
Original Publication Date: 1983-Feb-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 3 page(s) / 40K

Publishing Venue

IBM

Related People

Giaccone, LF: AUTHOR

Abstract

Disclosed is a computerized technique for organizing, recording and substantiating the connections among logic elements so as to save I-space and computation.

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Mechanism for Wiring Logic

Disclosed is a computerized technique for organizing, recording and substantiating the connections among logic elements so as to save I-space and computation.

I-space consists of a planar surface (chip) on which a grid of orthogonal lines is superimposed. The lines are called channels and are meant to serve as guides for wires which connect one part of the chip with another.

It is therefore possible to uniquely identify positions on the surface as the intersections of an x and y channel (i.e., x(i), y(j)) (Fig. 1).

If some point (intersection) x(i), y(j) is to be connected to some other point x(l), y(k) and the wire must traverse the guiding channels (i.e., cannot travel diagonally), then the minimum possible distance the wire must travel is 1/2 the perimeter of a rectangle r which has x(i), y(j) and x(l), y(k) at diagonal comers; r is termed the minimum enclosing rectangle.

If the path is to be minimum, it need not traverse the half perimeter. Its length is the same as the half perimeter, but the actual path of the wire could be anywhere within the rectangle (Fig. 2).

The connection q is therefore said to make a demand upon the space enclosed by the rectangle if the wire does not yet exist (is unsubstantiated). What is the demand? It is equivalent to a half perimeter, and the half perimeter consists of an x component (so many point to adjacent point traversals in the x direction) and a y component.

Since we do not know yet where the wire will go, we apportion this demand equally among the enclosed points. If, for instance, we have an n by m rectangle, then the x component of r is n points and its y is m. There are n-1 segments of wire traversing point to point in the x direction horizontal). Each of these x segments could occupy one of m positions (Fig. 3); therefore, we say th...