Electronic device, operation method of host, operation method of memory module, and operation method of memory device

An operation method of a memory module which includes a plurality of memory devices, the method comprising:

• receiving a partial write command including a partial write enable signal and a plurality of mask signals, at a first time;
• during a strobe toggle interval after the first time, receiving a first data strobe signal toggling through a first data strobe line connected with a first memory device, among the plurality of memory devices, and receiving a second data strobe signal maintained at logic high through a second data strobe line connected with a second memory device, among the plurality of memory devices;
• and
• receiving a plurality of data through a plurality of data lines, during a data input interval after the first time.