a write test circuit configured to generate test data and transmit the generated test data to an external memory device without storing the generated test data in a local memory device; and

a read test circuit configured to receive from the external memory device, read data that the external memory device has obtained by reading the generated test data, and compare the received read data with an expected value without storing either the received read data or the expected value in the local memory device, wherein

the write test circuit generates the test data according to a physical address of the local memory device, specified in a write command, and

the read test circuit is further configured to generate the expected value according to a physical address of the local memory device, specified in a read command.