A memory device having a memory core is described. The memory device includes a clock receiver circuit, a first interface to receive a read command, a data interface, and a second interface to receive power mode information. The data interface is separate from the first interface. The second interface is separate from the first interface and the data interface. The memory device has a plurality of power modes, including a first mode in which the clock receiver circuit, first interface, and data interface are turned off; a second mode in which the clock receiver is turned on and the first interface and data interface are turned off; and a third mode in which the clock receiver and first interface are turned on. In the third mode, the data interface is turned on when the first interface receives the command, to output data in response to the command.