Memory system, memory access interface device and operation method thereof

The present disclosure discloses a memory access interface device. A signal training circuit is configured for performing following steps. A transmitting circuit transmits a training data signal and a training data strobe signal as an output data signal and an output data strobe signal to a memory device according to timing reference signals. A read data signal from the memory device is received. The training data signal and the read data signal are compared to generate a comparison result indicating whether the read data signal matches the training data signal. The comparison result is stored. The clock generation circuit is controlled to modify a phase of one of the timing reference signals, further modifying the timing of one of the training data signal and the training data strobe signal, to be one of under-test phases to execute a new loop of a training process.