Logic simulator

摘要

A logic simulator is disclosed, in which a logic activity analyser (2) receives a network list (4) and macro cell data (5), and analyses the logical activity of a circuit which is to be simulated, for each macro cell, on the basis of signal changes which are given by signal change information from a signal change detector (1), in such a way that if a macro cell accepts an input signal of an unspecified value (X), the unspecified value (X) is replaced for one logical operation by a logical expression which propagates itself and is based on the input signal of its immediately previous macro cell, so that the logic simulator is put into a position to carry out a logic simulation without reducing the degree of integration and the efficiency of the logic circuit, which is actually to be manufactured, after the logic simulation. <IMAGE>