The present invention presents a non-volatile memory and method for its
operation that allows instant and accurate detection of erased sectors
when the sectors contain a low number of zero bits, due to malfunctioning
cells or other problems, and the sector can still be used as the number
of corrupted bits is under the ECC correction limit. This method allows
the storage system to become tolerant to erased sectors corruption, as
such sectors can be used for further data storage if the system can
correct this error later in the written data by ECC correction means.