Device for supporting error correction code and test method thereof

A device for supporting a test mode for memory testing according to an example embodiment of the inventive concepts may include a memory configured to receive and store writing data and output reading data from the stored writing data; an error correction code (ECC) engine configured to generate the writing data by encoding input data and to generate output data by correcting error bits of N bits or less included in receiving data when N is a positive integer; and an error insertion circuit configured to provide the reading data to the ECC engine as the receiving data in a normal mode and to provide data obtained by inverting at least one bit of less than N bits of the reading data to the ECC engine as the receiving data in the test mode.