The present invention relates to a double data rate interface and method for use between a processor and random access memory, comprising a delay line including means for creating a delay in a data strobe signal from the random access memory, the delay line being arranged such that the delay in the data strobe signal is equal to the sum of set-up time and data bus rise time. The interface of includes the delay line comprising the delay locked loop which in turn comprises a ring oscillator. The ring oscillator includes a buffer and a Vernier delay.