PURPOSE: To reduce the mounting density in a printed circuit board by transposing output pins of the printed circuit board for connection to a connection substrate to scramble data.

CONSTITUTION: The wiring order between an S/P converting part 121 and output pins of a printed circuit board 110 is changed in the printed circuit board 110 to scramble data as desired. The wiring order between input pins of a printed circuit board 130 and a P/S converting part 141 is changed in the printed circuit board 130 to descramble data as desired. Since wirings to input/output terminals of each printed circuit board are transposed in this manner in scramble data as desired, a scrambling IC in the printed circuit board is unnecessary and the mounting density in the printed circuit board is reduced.