| 摘要 |
<p>PURPOSE:To simultaneously perform data protective processes on two EEPROMs so as to reduce the writing time to the two EEPROMs by using a data protection control signal. CONSTITUTION:A selector 8a to which address signals 4 are inputted outputs EEPROM select signals 9-1 and 9-2 in corresponding to addresses at the time of writing data and, on the other hand, simultaneously selects two EEPROMs 6-1 and 6-2 on the basis of a data protection control signal 7 outputted from a CPU 1 at the time of performing a data protective process. In addition, data protective processes to the two EEPROMs 6-1 and 6-2 are simultaneously performed by making the data used for shifting the mode to a protective mode and data writing areas of the two EEPROMs 6-1 and 6-2 the same. Therefore, the writing time to the two EEPROMs 6-1 and 6-2 can be reduced, since the data protective processes to the EEPROMs 6-1 and 6-2 can be performed simultaneously.</p> |
