inselcntr and trcntr are control signals for controlling the selector circuits outcntr 1 and outcntr 2 are control signals controlling on and off of the buffer circuits outdata indata inselctrl outselcntr outcntr 1 and outcntr 2 are signals coupled to other circuit sections and included in wshsig in fig1 the circuit shown in fig1 differs from the circuit shown in fig7 in that the circuit in fig1 includes the functions of shaping and amplifying a signal passing through the lsi from the top surface to the bottom surface or vice versa when a signal input from wtvsig is to be transferred to wsvsig buf 1 is turned off the switch of the buffer is shut off to place its output in a high impedance state buf 4 is turned on the switch of the buffer is connected and outsel 2 is controlled by the trcntr signal to cause the output of buf 3 to be provided to the input of buf 4 when a signal input from wsvsig is to be transferred to wtvsig buf 1 is turned on buf 4 is turned off and outsel 1 is controlled by the trcntr signal to cause an output from buf 2 to be provided to the input of buf 1 when a signal from outdata is to be output to wsvsig buf 4 is turned off buf 1 is turned on and outsel 1 is controlled by the trctr signal to cause the signal from outdata to be provided to the input of buf 1 when a signal from outdata is to be output to wsvsig buf 3 is turned on buf 1.