| 摘要 |
PURPOSE:To facilitate finding of troubles due to an electrically rewritable ROM by indicating memory replacement when the electrically rewritable ROM where data of a total counter number is stored exceeds the number of times of rewritability. CONSTITUTION:This device consists of an electrically rewritable ROM1 where data of the total counter number is stored, a controller 2 which controls a high-voltage transformer, etc. and exchanges signals with an I/O port, an interface, etc. and controls the electrically rewritable ROM1, and a display device which indicates memory replacement when the electrically rewritable ROM1 exceeds the number of times of rewritability. The electrically rewritable ROM1 consists of a RAM cell 1a and a nonvolatile cell 1b having the same memory capacity, and stored contents of the RAM cell 1a are transferred to the nonvolatile cell 1b when a pulse STORE outputted from a CPU2 is inputted, and stored contents of the nonvolatile cell 1b are transferred to the RAM cell 1a when a pulse RECALL is inputted. |
