SEMICONDUCTOR MEMORY DEVICE AND NONVOLATILE SEMICONDUCTOR MEMORY DEVICE

摘要

PROBLEM TO BE SOLVED: To accurately perform internal read of memory cell data by compensating defective threshold voltage of a nonvolatile memory cell.

SOLUTION: A plurality of sense amplifiers (3, 4) are provided at a selection bit line, a remaining current (Irmn) corresponding to a current flowing in a memory cell and a reference current Iref being reference of threshold voltage of this memory cell are supplied to this sense amplifiers, and the current (Irmn) and the current Iref are sensed. Operation of the sense amplifier is controlled so that sense margins are different, defective margin is detected conforming to coincidence/noncoincidence of the logic levels of output signals of these sense amplifiers, and an address of the defective margin memory cell is registered.

COPYRIGHT: (C)2003,JPO