| 摘要 |
PURPOSE:To prevent improper use even when an individual identification number is intentionally read by coding a data when the individual identification number is written, decoding the data when the individual identification number is read and revising an erroneous data automatically when the error is correctable. CONSTITUTION:A CPU 10 is operated according to a program of a program memory ROM 11. Five serial decimal numbers from a ten-key 6 being BCH coded data are written in a number memory 14 according to a prescribed procedure in the case of write at first. Then in the case of read, the CPU 10 initializes an internal register and a data memory 12 and five data from the memory 14 are read into the memory 12. Then BCH decoding is implemented according to a prescribed procedure and error correction is implemented in the decoding process. When error correction is enable or no error is in existence in the decoding process, the number is confirmed as a serial number by the reverse prescribed procedure to the procedure above. The data is subject to BCH coding and it is compared with a BCH coding data stored in the memory 14, and when they are dissident, the BCH data is replaced with the corrected BCH coding data.
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