The Hitachi HM51(S)4170C are CMOS dynamic RAM organized as 262,144-word x 16-bit. HM51(S)4170C have realized higher density, higher performance and various functions by employing 0.8 m CMOS process technology and some new CMOS circuit design technologies. The HM51(S)4170C offer fast page mode as a high speed access mode. Multiplexed address input permits the HM51(S)4170C to be packaged in standard 400-mil 40-pin plastic SOJ and standard 400-mil 44-pin plastic TSOPII. Internal refresh timer enables HM51S4170C self refresh operation.