Delay element testing apparatus and integrated circuit having testing function for delay elements

摘要

A delay element testing apparatus has a signal generator for generating a plurality of signals, at least one of which is variable in timing; a phase comparator for making a comparison of a relationship in terms of phasic anteriority and posteriority between the signal passing through a delay element under test and the timing-variable signal among the plurality of signals; and a test result output circuit, controlled by a control signal generated by the phase comparator, for outputting a signal indicating a quality of a delay characteristic of the delay element under test. Main parts of this testing apparatus can be provided on a substrate to realize an integrated having a function for testing delay elements included therein.