An interface device according to the present invention interfaces with a host
by an m-bit unit. A flag signal generator circuit generates a mode flag signal
indicating whether a data transfer mode of the interface device is a multi-transfer
mode. A control circuit operates responsive to information indicating whether an
address from the host is a data width aligned address and whether the address thus
transmitted belongs to a data width aligned address range. The control circuit
causes m-bit data from the host to be continuously stored in a first-in first-out
memory. Data continuously stored in the memory is at once transmitted to a high-speed
bus connected to the interface device.
