US Patent 7203113 Semiconductor storage device

Disclosed is a semiconductor storage device in which control is performed in such a manner that if the refresh operation is not being performed when a chip-select signal undergoes a transition from an inactive (standby) state to an active state, read or write access is executed immediately and if the refresh operation is in progress when the chip-select signal undergoes a transition from the inactive state to the active state, a wait signal for causing read or write access to wait is generated by a wait generating circuit.