Patent ID: 8245170

Claim:
A timing library test apparatus comprising: a difference calculator configured to look into a look-up table in a timing library, the look-up table comprising a plurality of timing constraint values registered in association with a plurality of combinations between reference transient times of a signal at a reference terminal and constraint transient times of a signal at a constraint terminal, and to group neighboring two timing constraint values in the look-up table as one pair, respectively, and to calculate differences between neighboring two timing constraint values of a plurality of pairs; a determination part configured to determine whether the differences calculated by the difference calculator have a characteristic feature of increase inclination or decrease inclination; and a decision part configured to decide that the timing library has a singular point when the determination part determines that the differences does not have the characteristic feature, and to decide that the timing library does not have the singular point when the determination part determines that the differences have the characteristic feature.