Input-output devices are prevented from conducting false output due to
faulty operation by providing an input-output control apparatus
configured to store input-output values to be used by a processor to
conduct arithmetic operation in a mode having a relatively high safety
requirement, in a first storage area, store input-output values to be
used by the processor to conduct arithmetic operation in a mode having a
relatively low safety requirement, in a second storage area, and restrict
copying to the first storage area, copying from the first storage area,
copying to the second storage area, or copying from the second storage
area according to the mode concerning the safety requirement.