In a semiconductor device, the reset command input process may be executed by a simple method and circuit in a short period of time when a reset command is inputted compared to conventional art. A control circuit for the semiconductor device is adapted to control a clock generator for generating a system clock having a changeable frequency, wherein, in a normal operating mode of the semiconductor device, the control circuit changes the frequency of the system clock generated by the clock generator from a first frequency to a second frequency that is higher than the first frequency according to a reset command, and performs an interrupt process on the semiconductor device, so as to enter a reset sequence mode from the normal operating mode.