Design Of Multifunctional Communication Card Based On Reflective Memory

Distributed simulation system has the requirements of real-time, and it usually consists of reflective memory network, however the partial nodes of the system have the only communication interface of 1553 B, RS422, which can’t directly access the system. A multi-functional and real-time communication card which was developed based on the reflective memory technology in this article, can form reflective memory network, and it can achieve the data interaction between the data of 1553B、RS422 and the reflective memory network data. What’s more, it can achieve the data transmission between the nodes highly reliable and low-latency.Based on the analysis of communication networks and reflective memory technology, the data transfer mechanism of ring topology was proposed, the FRM(Fiber-Optic Reflective Memory) protocol and its data format was designed. Through modular thought, the card can be divided into optical communication module, computer interaction module, RS422 interaction module, 1553 B interaction module and memory module. In the optical communication module, SERDES together with SFP was used as an optical fiber transmission; data frame synchronization was achieved by the self-synchronization technology. The cross-clock transmission of signals was achieved by the secondary trigger together with asynchronous FIFO. The arbitration of multi-port data was achieved by the flow control state machine. In the computer interaction module, CPCI interface was achieved by the chip of PLX9054, and the protocol match was achieved by framing unit. In the RS422 interaction module, the UART IP was used as RS422 transceiver. In the 1553 B interaction module, the 1553 B interface was achieved by 1553 B IP core. In the memory module, DDR2 SDRAM was used as memory unit, which was controlled by UNIPHY IP core. Data exchanging between these modules was achieved through Avalon bus architecture. To meet the requirements of the board’s operating environment, the drivers was designed, which can operate both on the system of Windows and the system of RTX.Test results show that the multi-functional communication card based on the reflective memory technology can achieve reflective memory network, and it can also can achieve the real-time data exchange between the devices used 1553 B interface or RS422 interface. The board has high data transfer rate, low error rate, and the latency is predictable.