Synthesis of delay fault testable combinational logic

The synthesis of combinational logic which is robust delay fault testable is developed. In a circuit, any reconvergent fanout may result in the presence of blocked paths and/or paths which can be sensitized only if some other path is also sensitized. Implicit don´t care terms are used to detect these problems and a local transformation at the reconvergence point is used to upgrade the delay fault testability of the circuit. The sharing of terms in a multilevel circuit is preserved to the greatest extent possible. Good results have been obtained based on an implementation of the algorithm in the LISP programming language on a TI Explorer machine.<>