Nonvolatile semiconductor memory device using a command control system.

摘要

A nonvolatile semiconductor memory device using a command control system comprises a protect cell (116) composed of a nonvolatile memory cell, a protect sense amplifier circuit (117) for reading the data from the protect cell, a high-voltage sensing circuit (114) for supplying a voltage during a programmed operation such as a writing or an erasing operation, a protect control circuit (115) for controlling the protect cell, and a control circuit for reading the data from the protect cell and according to the read-out data, controlling the command to the memory cell array. Even if the device malfunctions due to an erroneous command entered as a result of power noise or command noise during command input, the destruction of the data in the memory cells can be prevented, which consequently increases the operating margin, improving the reliability. <IMAGE>