Nonvolatile memory devices, memory systems and related control methods

A method of operating a nonvolatile memory device comprising:

• receiving a read command from an external device, the read command including an address of the memory cells to be selected;
• transitioning a ready/busy signal from a ready state to a busy state in response to the read command, the ready/busy signal indicating one of ready state and busy state of the nonvolatile memory device;
• applying a bias voltage to at least one of the plurality of word lines and the plurality of bit lines coupled with the selected memory cells;
• sensing and storing sensed data of selected memory cells in a page buffer;
• dumping the sensed data from the page buffer to an input/output buffer;
• starting a recovery operation upon completing the dumping operation and, during the recovery operation, discharging the bias voltage applied to at least one of the plurality of word lines and the plurality of bit lines coupled with the selected memory cells;
• transitioning the ready/busy signal from the busy state to the ready state substantially on the starting of the recovery operation and before the completing the recovery operation;
• and
• outputting a read data corresponding to the read command substantially on the transitioning of the ready/busy signal from the busy state to the ready state.

A method of operating a nonvolatile memory device comprising:

• providing a first command to the nonvolatile memory device;
• detecting a point of time when a ready/busy signal of the nonvolatile memory device transitions from a busy state to a ready state;
• and
• providing a second command to the nonvolatile memory device,
• wherein issuance of the second command to the nonvolatile memory device is prohibited before a reference time elapses from the point of time the ready/busy signal transitions from the busy state to the ready state.