Double-pumped/quad-pumped variation mechanism for source synchronous strobe lockout

摘要

An apparatus for locking out a source synchronous strobe receiver, including a delay-locked loop (DLL) and receivers. The DLL receives a reference clock, and generates a select vector and an encoded select vector. The select vector is employed to select a delayed version of the reference clock that lags the reference clock by a prescribed number of cycles. The select vector is reduced by an amount and is gray encoded to indicate a first time. The receivers are each coupled to the delay-locked loop. Each of the receivers receives the encoded select vector and a corresponding strobe, and locks out reception of die corresponding strobe for a configurable lockout lime following transition of the corresponding strobe. The encoded select vector is employed by a gray code mux therein to determine the configurable lockout time by selecting a delayed version of the corresponding strobe.