| 摘要 |
PURPOSE:To easily set a first certification data and also to keep the secrecy of the internal data by supplying just once the certification data directly to a RAM right after the production. CONSTITUTION:The input of the certification numbers is instructed with operation of a keyboard 3 and the checking data is checked after each element and terminal are mounted at a production stage. In this case, a memory area in a RAM 15 is not specified and therefore the defect of the checking data is detected. Under such conditions, the first certification number can be written into a memory area. hereafter the checking data is properly checked. Thus it is not permitted to change the certification numbers before the certification numbers stored in the RAM 15 are supplied. As a result, the first certification number can be easily set and simultaneously the secrecy of the internal data is improved.
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