| 摘要 |
<p>PURPOSE:To obtain EEEPROM to execute essentially a normal action even to the destruction, etc., of a gate oxide film by writing the same data to the same address as a memory block provided in parallel, flagging a non-volatile flag in accordance with the quality of writing and selecting a reading block. CONSTITUTION:The same data latched to first and second input data latches 12 and 14 are written to first and second cell matrix blocks 10 and 11 provided in parallel and from the reading data from respective first and second output data latches 13 and 14 and the data of the latches 12 and 14, the quality of writing is decided by respective first and second verifyings 16 and 17. A non- volatile low unit flag to show the blocks 10 and 11 corresponding to each quality is flagged, the normal data from the one side selected blocks 10 and 11 through a block selector 19 at the time of reading are outputted, and even when the memory cell, in which the gate oxide film destruction occurs, exists for high density operation, EEPROM to execute always essentially the normal action is obtained.</p> |
