| 摘要 |
PURPOSE:To allow the titled system to cope with applications where data are rewritten frequently by adopting a constitution in which an active memory can be switched a standby memory at the time it is detected that the number of times of rewrite in the active memory reached a prescribed limit. CONSTITUTION:The data are written in an E<2>PROM-A at first, an operation flag in an address 0 is set to logical 1 and number of times of rewrite is set to 1. In applying data rewrite, 1 is incremented to the count and at the time of the value reaches a prescribed limit, the ROM-A is switched to a ROM-B. In this case, the flag of address 1000 of the ROM-B is set to 1 and the count is set to 1. The ROM-A used is informed to the operator by a display means and replaced. The ROM-B is used till its limit afterward. In using alternately the ROMs A, B in this way, the titled system is used for applications where data are rewritten frequently. |
