Test system and method

PURPOSE: A test system and a method thereof are provided to rapidly detect a fault on data path by comparing an output data and a test pattern data. CONSTITUTION: A memory device(110) includes a data I/O part. The data I/O part(112) is connected to a data entry path and a data read path. The data entry path is necessary for writing a data in a memory cell array(111). The data read path is necessary for reading a data saved in the memory cell array. A test apparatus(120) compares a output data and a test pattern data of the data I/O part. A test apparatus detects a fault on a data entry path or a data read path.