Method and apparatus for training a dll in a memory subsystem

Abstract

A method and apparatus for training a DLL in a memory subsystem is disclosed. In one embodiment, a memory subsystem includes a memory coupled to convey data read therefrom on one or more channels. Each memory channel may include a delay locked loop (DLL) configured to apply a desired amount of delay to a data strobe signal received from the memory during a read operation. Upon detecting a read request, a controller may initiate a training procedure in which the DLL is trained to the desired delay. During the training procedure, an input clock signal may be provided to the DLL. The delay within the DLL may be adjusted until an output clock signal has a desired phase relationship with the input clock signal. Once the desired phase relationship is attained, the training procedure may be terminated and the DLL input may be switched to receive the data strobe signal.