An engine control system that having an exhaust gas recirculation valve includes a first module that determines an EGR error and a second module that calculates a fuel injection timing based on the EGR error. This external ROM is previously memorized with player object data, basic shadow object data and light object data. The oscillator produces a timing and reference signal for the radio frequency unit based on control information from the controller. In operation, the memory monitors a power supply voltage coupled to the memory, and prohibits write or erase operations from being performed if the supply voltage drops below a predetermined value. By employing embodiments discussed herein, the ability of a chitosan-containing composition to properly solubilize at a desired time may be preserved.