A memory device in accordance with a described method of operation includes a read only memory (ROM) address controller and a suspend signal generator. The ROM address controller is configured to sequentially output a plurality of operation ROM addresses at which ROM codes to be executed in response to an operation command are stored, and to suspend output of the plurality of operation ROM addresses in response to a suspend signal. The suspend signal generator is configured to generate the suspend signal that is activated during a preset period depending on whether a suspend ROM address is identical to an operation ROM address, among the plurality of operation ROM addresses, currently being output. The suspend ROM address is an address at which a ROM code, execution of which is to be suspended, among the ROM codes, is stored.