SEMICONDUCTOR CIRCUITS CAPABLE OF SELF DETECTING DEFECTS

A digital circuit and a method for operating the same. The digital circuit includes (a) MxN regular cells electrically arranged in M rows and N columns, (b) N reference cells corresponding one-to-one to the N columns, and (c) N comparing circuits corresponding one-to-one to the N columns. Each regular cell is electrically coupled to a comparing circuit. Each reference cell is electrically coupled to the associated comparing circuit. Each regular cell includes a first tap node. Each reference cell includes P tap nodes. If a first voltage of the first tap node of a regular cell is between two voltages of two tap nodes of the P tap nodes of the associated reference cell, then the associated comparing circuit is capable of generating a first signal. If the first voltage is not between the two voltages, then the associated comparing circuit is capable of generating a second signal.