<p>Disclosed is a host device, wherein a card controller (21) receives data from a media card (23) through a socket (22). A read clock is transmitted by a primary transmission line (37), and data is transmitted by a data transmission line (38). The read clock is drawn out from the card controller (21) by an outward transmission line (39) and drawn back to the card controller (21) by an inward transmission line (40) thereafter. The outward transmission line (39) and the primary transmission line (37) have equal delay amount, and the inward transmission line (40) and the data transmission line (38) have equal transmission delays. The card controller (21) synchronizes with the read clock drawn back by the inward transmission line (40) and receives data.</p>
