| 摘要 |
A semiconductor memory comprises a memory array storing information that determines an activated state and an activation control circuit which causes a latch circuit to latch the activation information by referring to the memory when a given command is input after activation. It also comprises a memory cell for storing data, managed on a sector basis, and a second memory cell array for storing sector protection information. The control circuit then determines whether the memory cell array should be erased on the basis of the activation information latched in the latch circuit and the sector protection information stored in the second memory cell array. If the power supply voltage is lower than a particular level, the latch circuit latches activation information again when the given command is input again and if the voltage is higher than this level, the activation information is not latched again. Also disclosed is a memory device having two latch circuits, one for latching activation information and one for latching erase information. |
