To reduce test costs by reducing the number of pattern generators provided to a test apparatus. A test apparatus that tests a device under test and a test method are provided, the test apparatus comprising: a packet transmitting unit that packetizes and transmits, during a test of the device under test, a test pattern to be supplied to the device under test; a packet transferring unit that transfers a packet transmitted by the packet transmitting unit; a packet receiving unit that receives the test pattern transferred via the packet transferring unit; a buffering unit that buffers the test pattern received by the packet receiving unit; and a test signal supply unit that supplies the device under test with a test signal according to the test pattern acquired from the buffering unit.

Systems and methods disclosed herein provide for generating extra variables for an ATPG system utilizing compressed test patterns in the event an ATPG process is presented with faults requiring a higher number of care-bits than can be supported efficiently by the current hardware. The systems and methods provide for a multi-stage decompressor network system with an embedded serializer-deserializer. The systems and methods use a XOR decompressor in a first stage and a serializer-deserializer in conjunction with a second XOR decompressor in a second stage.