Embedded multimedia card (eMMC), host for controlling the eMMC, and methods of operating the eMMC and the host

A method of operating an eMMC system includes receiving a first command defining a first operation from the host, and storing the first command in a first command register among N command registers, and receiving a second command defining a second operation from the host, and storing the second command in a second command register among the N command registers, wherein the second command is received while the first operation is being performed.