A design of timing conversion interface between PXA270and peripherals based on FPGA is introduced,in order to solve the problem of timing matching when the ARCNET protocol chip COM20020is connected to the processor of central control unit(CCU)PXA270in train communication network.And an additional moduleDMA is designed in the FP-GA to ease PXA270’s burden.The test result of the whole network shows that this solution solves the timing matching problem and enhances response capability of the network.