| 摘要 |
PURPOSE:To prevent the leakage of a program by vanishing a program on a program storing RAM when an underwater sailing body completes action and the power source is turned off. CONSTITUTION:When an underwater sailing body is activated, a DMA (direct memory access) circuit 6 functions, a program in an electric erasing ROM 3 is transferred to a program storing RAM 7, and after the transfer is completed, an erasing circuit 8 generates the erasing voltage and the program in the electric erasing ROM 3 is eased. Further, when the underwater sailing body is started, a CPU 1 successively reads and executes the program transferred to a program storing RAM 7, at this time, for a data storing RAM 4, the intermediate result of the processing is stored and the input output of the signal with an external part are executed by an I/O port. When the underwater sailing body completes the action and the power source is turned off, the program in the program storing RAM 7 is naturally vanished. Thus, even when the sailing body is caught by the third party, the program is not decoded. |
