The M28W640FCT and M28W640FCB are 64 Mbit (4 Mbit x 16) non-volatile Flash memories that can be erased electrically at block level and programmed in-system on a Word-by-Word basis using a 2.7V to 3.6V VDD supply for the circuitry and a 1.65V to 3.6V VDDQ supply for the Input/Output pins. An optional 12V VPP power supply is provided to speed up customer programming.
More details:http://www.icchipword.com/article/M28W640FCB70N6E-Datasheet-PDF-NOR-Flash-PARELLEL-STD-FLASH-64-MEG-TRAY-STMICRO.html
NUMXS00109-1.pdf