A nonvolatile memory device includes a nonvolatile memory, a volatile memory being a cache memory of the nonvolatile memory, and a first controller configured to control the nonvolatile memory. The nonvolatile memory device further includes a second controller configured to receive a device write command and an address, and transmit, to the volatile memory through a first bus, a first read command and the address and a first write command and the address sequentially, and transmit a second write command and the address to the first controller through a second bus, in response to the reception of the device write command and the address.