Abstract: In a memory selectively operable in an active and a standby mode, a first oscillation signal of a first frequency is produced by an oscillator (35a or 35b) in the standby mode so as to reduce electric power consumption, instead of a second oscillation signal which is produced in the active mode and which has a second frequency higher than the first frequency. The first and the second oscillation signals are selectively supplied as a substrate voltage to a substrate (20) through a substrate voltage production circuit (36). The oscillator may comprise a first circuit portion (46 to 48) for oscillating the second oscillation signal and a capacitor circuit (51 to 53) connected to the first circuit portion through a second circuit portion (56 to 58) in the standby mode so as to generate the second oscillation signal.

Abstract: A precharge circuit which suppresses a peak of a charge current in conducting a precharge operation is disclosed.The precharge circuit comprises a precharge transistor for feeding the precharge current and means for generating a precharge control signal which changes slowly only when the precharge control signal is near an intermediate level of the specified binary levels of the precharge signal and changes quickly when the precharge control signal is not near the intermediate level.