NONVOLATILE MEMORY DEVICE HAVING FLAG CELLS FOR STORING MSB PROGRAM STATE

摘要

A nonvolatile memory device having flag cells storing MSB(Most Significant Bit) program state is provided to increase production yield of the nonvolatile memory by decreasing error in a process of reading data of a memory cell on the basis of MSB program of a selected row. A memory cell array(200) includes memory cells arranged in rows and first columns and flag cells arranged in the rows and second columns. A page buffer circuit(240) is constituted to read flag data bits from flag cells belonging to a row selected through the second columns. A judgement circuit(260) judges whether memory cells belonging to the selected row are programmed with MSB(Most Significant Bit) data, on the ground of flag data bits read out by the page buffer circuit.