A microcomputer is provided having a memory card interface capable of correctly latching data even when a card such as an MMC card is connected thereto. In the microcomputer having an interface with an external device such as a memory card, the interface unit is provided with an output driver connected to an external terminal for outputting a clock signal to output the clock signal and with an equivalent load circuit capable of imparting, to the clock signal extracted from an arbitrary position in a stage previous to the output driver in a clock signal path, delay equivalent to delay resulting from an external load connected to the external terminal in order to generate a clock signal for latching data inputted from the memory card.