A semiconductor memory apparatus includes a data input enable signal generation block configured to sequentially delay a data strobe signal to generate a first delayed data strobe signal, a second delayed data strobe signal, a third delayed data strobe signal and a fourth delayed data strobe signal, and generate a data strobe enable signal in response to a CAS write signal, a CAS write latency signal and the first to fourth delayed data strobe signals, a latch control signal generation block configured to output the data strobe signal as a latch control signal during an enable period of the data strobe enable signal, and a data latch block configured to latch data in response to the latch control signal and output latched data.