Abstract: In an ECU for controlling an engine, a microcomputer executes a program in a mask ROM after releasing the reset, determines a signal of a specific input terminal, and switches in accordance with the foregoing determination result the self operation mode into either one of the normal mode to execute a control program in a flash ROM and the rewrite mode to update and write a data from an external unit into the ROM. A monitor circuit monitors a watchdog pulse from the microcomputer, outputs a reset pulse to the microcomputer when determining an abnormality, and alters the level of the foregoing signal to the microcomputer into the level of the normal mode into the level of the rewrite mode.

Abstract: In an eyeglass lens grinding apparatus for grinding a periphery of a lens, a lens holding system holds a lens while clamping the lens. A data input system inputs shape data of an eyeglass frame to which the lens is fitted, and layout data of the lens with respect to the eyeglass frame. An edge-position-data calculating system obtains edge position data of the lens after layout, on the basis of the data inputted by the data input system. A first measuring system measures an edge position of the lens before processing that is held by the lens holding system, on the basis of the edge position data obtained by the edge-position-data calculating system. A second measuring system measures an edge position of the lens after rough grinding, on the basis of the edge position data. A chamfering-process-data calculating system obtains chamfering process data for processing a corner portion of an edge of the lens after finish processing, on the basis of a result of measurement by the second measuring system.