Herein disclosed is a method for controlling a semiconductor integrated circuit having plural domains, the method including controlling plural power supplies which supply power to the plural domains, controlling an asynchronous bridge section being provided between each of the domains, receiving and transmitting data for dynamically changing a power supply voltage of at least one of the domains, wherein, when a power supply voltage of one of the domains is substantially equal to a power supply voltage of the other domains, switching the power supply paths so as to supply the power supply voltage from one power supply to at least two of the domains, and switching the data paths so as to receive and transmit data between the at least two of the domains by bypassing the asynchronous bridge section.