A read/write memory having timed-out control of certain of its peripheral circuitry is disclosed. The control circuit for controlling the time at which time-out is to occur includes two delay stages of different lengths. The shorter delay stage is used to define the time-out in a read operation, and the longer delay stage is used to define the time-out in a write operation, since a read operation can generally be accomplished sooner than a write operation. Enabling of the periphery is controlled by an address transition detection circuit, and by a data transition detection circuit. The circuit includes a short path by which enabling of the periphery is performed responsive to a data transition in the absence of an address transition, in order to perform a late write operation.