Gigabit Rate Data Transfer Through Coaxial Cable


In the current plans for the pixel upgrade the data from the chips of one stave will be sent out through the End of Stave Controller to multiplex into high speed data transmission with reduced cabling. This location is exposed to extremely high doses of radiation and the requirement inner most pixel layers extractable also forces the transmission cable to stay at lower radius for several meters before exiting PP1. This makes the use of optical fibers for data transfer problematic. Further more, with the preferred CO2 cooling taking the system down to lower temperatures, the difficulties with low temperature for current optical components are also suggesting alternative solutions. Therefore we want to investigate the transfer of data at high rates through coax cable. Things to be checked include


To conduct the tests we use a Virtex 4 chip (FX20). This chip has 8 MGT transceivers that are capable of GBit rates. FPGA logic implements an error bit rate tester running on the MGTs. Initially we use the ML405 Xilinx evaluation boards for our testing. These boards will be replaced with custom made boards that allow for the use of different types of connectors by plugging PC boards that carry the connector into the main test board.


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Last modified: Mon Apr 7 2008 by Martin Kocian