The semiconductor device includes: a select circuit which selects, from output signals of tiding generators, timing signals formed by one timing generator; another select circuit which is disposed in a stage after the select circuit, and selects the tiding signals selected by the first select circuit or signals regulated in polarity, and outputs the selected signals outward; and a control register provided for variably setting the polarities of the signals regulated in polarity in units of the signals. If abnormal power supply cutoff of the semiconductor device is detected, the second select circuit is switched from the state of selecting the timing signals to the state of selecting the signals regulated in polarity in response to the detection.