The M58LW064 is a non-volatile Flash memory that may be erased electrically at the block level and programmed in-system on a 16 Word or 8 Double-Word basis using a 2.7V to 3.6V supply for the circuit and a supply down to 1.8V for the Input and Output buffers. The M58LW064A is organised as 4M by 16 bit. The M58LW064B has 4M by 16 bit or 2M by 32 bit organisation selectable by the Word Organisation WORD input. Both devices are internally configured as 64 blocks of 1 Mbit each.