SEMICONDUCTOR STORAGE DEVICE

PROBLEM TO BE SOLVED: To realize a flash writing function by which data are written into a plurality of memory cells simultaneously in a semiconductor storage device. SOLUTION: Power supply side sensing amplifier driving signals SAP1 and SAP2 of 2 systems and ground side sensing amplifier driving signals SAN1 and SAN2 are inputted to a sensing amplifier 13. If the level of the signal SAP1 is 'H' and the level of the signal SAN1 is 'L', a bit line BL is driven to a power supply potential and a bit line NBL is driven to the ground potential. On the other hand, if the level of the signal SAP2 is 'H' an the level of the signal SAN2 is 'L', the bit line BL is driven to the ground potential and the bit line NBL is driven to the power supply potential. As the bit line potentials can be set by the sensing amplifier, a circuit which sets the bit line potentials during a flash writing operation and is necessary in a conventional constitution is not necessary.