The Design Of TCN High Speed Train Gateway Based On VME Bus

Train gateway is the equipment on the train which Connects high speed train communication network's main line MVB (Multifunction Vehicle Bus) and WTB (Wire Train Bus). It can be seen the gateway in the train network is the very important equipment because data cross the two line transmission. Gateway must be very high reliability and stability, So that data cross the two line transmission will be unmistakable.This Thesis introduced the gateway includes three subequipments, therefore needs to have one reliable high back board line to connect the three subdevices. The VME bus is one kind of general computer buses.the VME system already developed perfectly after it underwent more than twenty years promotion and it had been used in many domains such as industrial control, military system, aerospace, transportation and medical service. Therefore selected the VME line to take gateway's back board bus might enhance the train gateway stability.This Thesis introduces the train gateway's structure also analyses the VME line stardard and system function demand and uses FPGA to realize the VME bus logical control. The Thesis's task is the design for VME bus hardware of each submodule's interface and as to the software. Consider of gateway's major function is the data repeater, Simultaneously also uses the interrupt informs the CPU interruption program, therefore the interface of hardware's design contains the VME data transfer bus,priority interrupt bus and common bus signal. Consider of the driving force request for VME different signal, the design of driving circuit must be according to the electrical specification of VME agreement.The VME bus control logic realizes is used Altera Corporation's cyclone series chip.The software design divides two partly: master and slave, The internal modules of master FPGA equipment mainly include: the local bus cycle, the VME bus cycle, data buffer FIFO, the interrupt processing module, timer module and so on. The internal modules of slave FPGA equipment mainly include: the VME bus cycle, the interrupt request module, timer module and so on. It caused the above modules according to the VME line agreement stipulation sequential working.High speed train gateway VME line realized had been completed and already had interconnection with many kinds of MVB and WTB equipments.It passed the project approval smoothly. The gateway work is stable and reliably, each target satisfies the request.