| 摘要 |
PROBLEM TO BE SOLVED: To prevent the damage of productivity as the confidential property of data is ensured when data on re-writable involatile memory is written. SOLUTION: The connection state of two change-over switches before and after decoding processing by a master ROM 22 in a microcomputer 20 is set to the (2) side during writing of first data and switched to the (1) side on and after second data writing. Thereby, decoding processing is not effected on data during first data writing and after decoding processing is made on data available on and after second data writing without fail, the data is respectively written at a flash ROM 23. Thereby, since, at first data writing, input data may be ordinary data, a work procedure is simple, a writing time is shortened, and productivity is improved. Since, on and after second data writing after delivery to a market, there is a need to use coding data, the confidential property of data is ensured and changing of data is reliably prevented. |
