A nonvolatile memory system is provided. The memory system includes a nonvolatile memory device and a memory controller. The memory controller transmits first to fourth control signals to the nonvolatile memory device, sends a command, an address, and input data via a data bus, and receives output data via the data bus. The nonvolatile memory device receives the first to fourth control signals, and recognizes signals received via the data bus at a rising edge or a falling edge of the fourth control signal, as one of the command, the address, and the input data in response to the first to third control signals, and transfers the output data to the memory controller via the data bus based on the fourth control signal.