A
semiconductor integrated circuit device is provided, the circuit being capable of arranging a
control signal system, avoiding a danger of failure to check an indefinite
signal propagation prevention circuit or the like, further facilitating a check oriented to mounting on an automated tool, and facilitating power shutdown control inside of a
chip. In the
semiconductor integrated circuit device, power shutdown priorities are provided by independent
power domains Area A to Area I. A rule is provided, the rule defining that, in the case where a circuit having a high priority is turned ON, a power domain having its
lower priority cannot be turned OFF, thereby facilitating a designing method. In addition, areas capable of applying still another power supply are provided in the independent power areas Area A to Area I. In that area, a
relay buffer (
repeater) and a
clock buffer or an information retaining latch for saving information are integrated. A
layout may be provided in a direction vertical to a direction in which cells are arranged in a row direction for the purpose of dispersing a current of a light supply line.