 Image Number 4 for United States Patent #7225372.
A testing circuit using ALPG is mounted in a testing board in which sockets for mounting semiconductor memories as devices to be tested in the board is mounted and a volatile memory for storing a data table for generating a random pattern is provided in the testing circuit so that a test using a test pattern having no regularity is performed using the data table in addition to a test using a test pattern having regularity generated by the ALPG.
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