A device for definition of the waiting time which should pass in a clock-controlled memory circuit after the start of a specific operation until a subsequent operation may be started. The device includes a digital timer which is arranged in the memory circuit, is switched on when the specific operation is initiated and allows the subsequent operation to be started after a defined time period has elapsed. The digital timer, after it is switched on, counts periodic counting pulses which are derived from the clock signal, in order to signal the end of the waiting time as soon as it has counted a desired number of these pulses. A waiting time adjustment apparatus is provided and is accessible via external connections of the memory circuit in order to set the desired number of counting pulses.