| 摘要 |
<p>PURPOSE:To prevent the leak of a program by reading a program housed to an ultraviolet erasing ROM to a RAM, executing the program and erasing the program on the RAM when operation is finished and a power source is interrupted. CONSTITUTION:A DMA circuit 6 is operated by the activation of a crusing object and the program housed to the ultraviolet erasing ROM 3 is transferred to a program housing RAM 7. After the transfer is completed, an ultraviolet generating circuit 8 is operated to generate ultraviolet rays 9. Then, the program housed in the ultraviolet erasing ROM 3 is erased. The program transferred to the program housing RAM 7 is successively read and executed by a CPU 1. The intermediate result of processing is housed to a data housing RAM 4 and the input/output of a signal is executed with an external part by an I/O 5. When the operation of the crusing object is finished and the power source is interrupted, the program in the program housing RAM 7 is naturally erased.</p> |
