Graphene is an emerging nano-material that has garnered immense research interest due to its exotic electrical properties. It is believed to be a potential candidate for post-Si nanoelectronics due to high carrier mobility and extreme scalability. Recently, a new graphene nanoribbon crossbar (xGNR) device was proposed which exhibits negative differential resistance (NDR). In this paper, we present an approach to realize multistate memories, enabled by these graphene crossbar devices.