BUS CONTROL SYSTEM

PURPOSE: To prevent band widths from decreasing at the time of degenerate operation by providing fault resistance withstanding to a one-point fault only by adding slight redundancy. CONSTITUTION: One alternative signal line S0 is provided for data lines D00-D70 and a parity line P0 as a unit of the generation of a parity signal. If a fault occurs in a line, the signal to be sent by the line where the fault occurs is transmitted by the alternative signal line S0 through a transmission-side parity generation substitutive control circuit 120 and put back to the original line by a reception-side parity inspection substituting circuit 200, thereby making the alternative signal line substitute for the faulty line.