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# Interface for the Verification of Two Level Designs

IP.com Disclosure Number: IPCOM000082225D
Original Publication Date: 1974-Oct-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 14K

IBM

Roth, JP: AUTHOR

## Abstract

The function performed by a primitive device may be defined by a number of implications, "IF - THEN" statements. If each variable of the function is two-valued, then the definition of the function or design may be described by an array of "cubes" assuming that the primary input variables are ul through ur and the output variables, vl through vt. Relation between the input and output variables describing the function would be given by a cube, consisting of the assignment of 1's or 0's to any of the input and output variables. If a given variable is not assigned, then it is given the value x, to denote unknown or indeterminate.

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Interface for the Verification of Two Level Designs

The function performed by a primitive device may be defined by a number of implications, "IF - THEN" statements. If each variable of the function is two- valued, then the definition of the function or design may be described by an array of "cubes" assuming that the primary input variables are ul through ur and the output variables, vl through vt. Relation between the input and output variables describing the function would be given by a cube, consisting of the assignment of 1's or 0's to any of the input and output variables. If a given variable is not assigned, then it is given the value x, to denote unknown or indeterminate.

The interpretation of this "cube" is that if the input variables which are "bound" have the values assigned, then the output variables will also take on their values. An array of such cubes may be called an that they be consistent; this means that if two cubes have common input interfaces, then also they have common output interfaces. The absence of a common output interface under this condition would mean that the cubes have conflicting, inconsistent, requirements for their outputs.

Array Logics are of pertinent interest today in the arena of large scale integration (LSI) design, because they promise certain features which LSI designs need so badly: the ability to represent a wide variety of functions, so that they have a kind of universality, and as a consequence of this, the ability to be modified - behavior modification. In the design of computers, many engineering changes are made. If the ability o make these changes quickly is not available and current methods do not - then costs and time for design spiral.

The problem of design of Array Logics satisfying the definition of some desired functions has been studied for many years, and in recent years with quickening interest because of the possible LSI connection. A number of algorithms and programs by the author has been devoted to methods for optimization of two-level designs. Optimization does not necessarily mean minimization, for the problems may be so complex that minimization is out of the question, while on the other hand, approximate methods can do when performed on a computer vastly mo...