ERASE METHOD IN FLASH MEMORY CELL

摘要

PURPOSE: An erase method in a flash memory cell is provided to prevent an over erasing by a sector and performing an erase identifying operation by a sub-sector, and simultaneously performing a recovery operation to other sub-sectors during an erase identifying operation. CONSTITUTION: A pre-program is performed by a sector according to an erase command(101,102). A pre-program identifying operation is performed and it is identified whether the pre-program is normally performed(103). It is identified whether the number of counter looping is the number of last looping when the pre-program is not normally performed(104). It is formed that an erase state is defected when the number of counter looping is the number of last looping(121). The number of counter looping is increased and the pre-program is performed when the number of counter looping is not the number of last looping(105). It is identified whether a current address is a last address when the pre-program is normally performed(106). The current address is increased and the pre-program is performed when the current address is not the last address(108).