Patent ID: 7277329

Claim:
An erase method used in an array of non-volatile memory cells arranged in a plurality of sectors, each sector having an erase flag, the method comprising: setting the erase flag of sectors selected to be erased to a first value; sequentially verifying memory cells in sectors beginning from a first sector to a last sector whose erase flag is set to the first value and for each sector beginning from a first address to a last address; when verification fails, applying an erase pulse to the sector and verifying a memory cell at the same memory address again if a value of a erase-times counter is less than an erase-skip value, verifying the remaining sectors whose erase flag has the first value if the value of the erase-times counter reaches the erase-skip value; when each memory cell of a sector to be erased passes verification, setting the erase flag of the sector to a second value; when the erase flag of each sector selected to be erased is set to the second value, terminating the erase operation.