In the single bit and have multiplex bit mode the non-volatile semiconductor memory device and its programming movement and the read-out operational mannered null

摘要

A nonvolatile memory having a memory field and a redundant field within a single semiconductor chip is disclosed. The memory field is provided to store normal data and the redundant field is provided to store essential device data. The nonvolatile memory includes a plurality of first page buffers performing a multi-bit reading operation for the memory field and a plurality of second page buffers performing a regular single-bit operation for the redundant field. A time period of the regular single-bit operation for the redundant field is shorter than that of the multi-bit operation for the memory field. The nonvolatile semiconductor memory of the invention is therefore capable of performing single-bit operation at a higher speed than the conventional nonvolatile semiconductor memories each having the single- and multi-bit operation modes, improving their performance.