In accordance with the present invention a data processing circuit includes a first data path for processing first data. The positioning units each have an end fixed to the light guide plate, an opposite end fixed to the backplane, and an intermediate portion which is provided with a positioning section. A sheath provided with a channel is pivotally mounted with respect to the hub and is positioned in an initial position in which the through opening in the protector is closed by the sheath. The photonic crystal component has an array of a plurality of plastic elements having longitudinal axes and forming a 2-dimensional photonic crystal structure with a predetermined lattice constant. Thus, it is possible to actualize the selective initialization on the prescribed sub-areas within the working RAM without increasing the scale of the peripheral circuitry, without requiring complicated controls, and without increasing the overall processing time therefor.