In an embodiment, a semiconductor memory device includes a clock latency that can be controlled responsive to whether or not an output order of burst data is reordered. The semiconductor memory device may comprise a control unit and a latency control unit. The control unit may generate a latency control signal having a logic level that varies depending on whether or not an output order of burst data is reordered. The latency control unit may control a latency value in response to the latency control signal. The semiconductor memory device and the method of controlling the latency value responsive to a reordering of the burst data allow for an optimally fast memory access time.