A memory card includes a first signal terminal configured to output a first signal; a second signal terminal configured to output a second signal, the first and second signals being complementary to each other; and a controller configured to drive the first and second signal terminals to have a negative state until a link connection is performed after power is supplied to the memory card. When a level of the first signal is greater than a level of the second signal, the first and second signal terminals are in a positive state, whereas when a level of the first signal is smaller than a level of the second signal, the first and second signal terminals are in the negative state.