For control, some memory circuits use a delay-locked loop to generate a set of
signals, each delayed a different amount relative a reference signal. However,
as circuits get faster and faster, conventional delay-locked loops require use
of extra interpolation circuitry to generate smaller delays, and thus consume considerable
power and circuit space. Accordingly, the inventor devised a circuit which interlaces
and synchronizes two delay-locked loops, each including a number of controllable
delay elements linked in a chain. In one embodiment, the first loop produces a
sequence of clock signals delayed an even number of delay periods relative a reference
clock signal, and the second loop produces a sequence of clock signals delayed
an odd number of delay periods relative the reference clock signal. In addition,
the first and second loops are synchronized.