High speed data transferring technology in TOF trigger system of BES-III

The TOF (Time-of-fight) trigger system of BES-III (Beijing Spectrometer III) is faced with the demand of transferring massive high speed data: receiving 368 fast hit signal from the Front-End-Electronics synchronous with the 41.7 MHz dock, sending the processed 4 bits hit number information and 3 bits back-to-back information to the Global-Trigger-Logic with real time, sending processed 136 bits position information to the Track-Match-Logic with real time, and it is desired to provide all the data packet to the DAQ system every 16 valid events, for off-line analysis. During the design, we employed different technical means, such as serialize/de-serialization, fiber, LVDS, VME bus, to achieve the different data transferring requirement. This paper describes the methods we applied in the design. (authors)