<p>A card controller (4) includes a rewritable non-volatile memory (5) and an IC card chip (6). The card controller can output outside at least one of the reset response information (ATR) which is outputted by the IC card chip in response to the resent instruction to the IC card chip and the information indicating the erase unit of the flash memory, in response to a predetermined command issued from outside. A card host references the reset response information and can make the card controller change the IC card chip operation speed or the operation frequency. When rewriting the storage information in the non-volatile memory, the card host references the information indicating the initialization unit so that it can send an amount of write data matching with the initialization unit before issuing a write instruction.</p>
