An object of the invention is to make effective use of the structure of a multilayered semiconductor device that uses penetration electrodes in such a manner that the layered chips obtain stable internal power supply voltages with no increase in current consumption or in the area of the layered chips. The braking feature will maintain lowered crossing gate arms in the horizontal position when a train is approaching and until it is the proper time to raise the gate arms. The threshold current modifying device includes a threshold current calculating module and a power control module.