METHOD AND DEVICE FOR COMPRESSING AND EXPANDING DATA PATTERN

摘要

A method by which a test pattern to be applied onto an IC for testing can be compressed efficiently. The method comprises determining the number phi of data transitions of the pattern at every pin of the IC and the entropy H of the data, distributing the test pattern among a block wherein the phi is smaller than a threshold phi M ( phi < phi M), a block wherein the phi is larger than the threshold phi M ( phi > phi M) and the H is larger than a threshold HM (HHM) (411), compressing the block wherein phi < phi M by the run-length compressing method, compressing the block wherein phi > phi M and HHM by the LZ compressing method.