Semiconductor memory device having data protection feature

摘要

A reset power down mode designating signal and first and second write protect signals are provided to a control circuit. According to the states of these external control signals, the status of unconditional inhibition, unconditional permission, and lock bit (LB) dependency for the protect status of data rewrite is set for each memory block group of a memory array. Therefore, the write protect status can be set in a flexible manner for a nonvolatile semiconductor memory device.