A FLASH EPROM device includes a memory array organized into a plurality of blocks of memory cells. An energizing circuit applies energizing voltages to the blocks of memory cells to read and program addressed cells, and to erase selected blocks or the whole memory array. An erase verify circuit separately...http://www.google.de/patents/US5414664?utm_source=gb-gplus-sharePatent US5414664 - Flash EPROM with block erase flags for over-erase protection
