An interface circuit includes: a packet transmitter configured to generate a plurality of transmission packets based on a request, which is output from a core circuit, and output the plurality of transmission packets, the plurality of transmission packets including information indicative of being a packet to be merged; and a packet receiver configured to generate a merged packet by merging a plurality of extension packets from among a plurality of reception packets received from outside the interface circuit, the plurality of extension packets including information indicative of being a packet to be merged.