A multi-port volatile memory device can include a first port that is configured for data transfer to/from an external host system and the device. A volatile main memory core is configured to store data received thereat and read requested stored data thereform. A volatile sub memory core can be configured to store data received thereat and read requested stored data therefrom. A main interface circuit can be coupled to the first port and can be configured to provide data to/from the volatile main memory core and the first port in a master mode and can be configured to provide data to/from the volatile sub memory core and the first port in a slave mode. A second port can be configured for data transfer to/from an external non-volatile memory device and the device and a sub interface circuit can be coupled to the second port and configured to provide data to/from the volatile sub memory core and the second port in the slave mode.