Memory device, memory system, and operation method of memory device

An operation method of a memory controller configured to control a memory device, the method comprising:

• transmitting a mode register write (MRW) command to the memory device for setting, as a ZQ mode, one of a background calibration mode and a command-based calibration mode in a first mode register of the memory device;
• and
• controlling the memory device to perform a ZQ calibration based on the ZQ mode which is set in the first mode register of the memory device,
• wherein when the command-based calibration mode is set in the first mode register as the ZQ mode, the memory device performs the ZQ calibration in response to a ZQCal start command received from the memory controller;
• and
• wherein when the background calibration mode is set in the first mode register, the memory device the ZQ calibration with a time interval corresponding second information specified in the first mode register, and
• wherein when the background calibration mode is set in the first mode register, the memory device ignores the ZQCal start command from the memory controller.

A memory system, comprising:

• a memory device including a first mode register;
• and
• a memory controller configured to control the memory device to perform a ZQ calibration, wherein the memory device is configured to:
• select, as the ZQ mode, one of a background calibration mode and a command-based calibration mode based in the first mode register,
• when the selected ZQ mode indicates the command-based calibration mode, perform the ZQ calibration in response to a ZQCal start command received from the memory controller;
• and
• when the selected ZQ mode indicates the background calibration mode, perform the ZQ calibration with a time interval corresponding second information specified in the first mode register, and
• wherein when the selected ZQ mode indicates the background calibration mode, the memory controller is further configured to ignore the ZQCal start command from the memory controller.