Speaker
Description
Summary
We have designed and built an FPGA-based platform for users of high speed optical links in high energy physics experiments. The Gigabit Link Interface Board serves both as a platform for the evaluation of optical links in the laboratory as well as a triggering and/or data acquisition system in beam or irradiation tests of detector modules. The major hardware component is a double width Advanced Mezzanine Card (AMC) that can be used either on a bench or in a μTCA crate. One of the main advantages of the GLIB AMC is the presence of two FPGA Mezzanine Card (FMC) sockets providing additional clocks and user-specific I/O. In order to enhance the GLIB AMC compatibility with legacy and future triggering and/or data acquisition interfaces as well as its I/O bandwidth when in bench-top operation we have developed some auxiliary add-in cards. The first auxiliary add-in board developed is an FMC based on a commercial Clock & Data Recovery (CDR) integrated circuit for interfacing the GLIB AMC with the TTC system used currently in the LHC experiments. The TTC FMC is able to receive the 160Mbps bi-phase mark encoded bit-stream from an optical source, extract the clock and the data and forward them to the FPGA of the carrier card for further decoding of the data stream. This FMC mainly serves for bench-top systems, since the GLIB AMC can receive TTC information through the backplane when inserted in a μTCA crate. However, the TTC FMC could also serve even in μTCA systems that do not incorporate special hardware for TTC reception and distribution through the backplane (e.g. the CMS-designed AMC13). Another board under development is the Versatile Link FMC, a mezzanine card that interfaces the various flavors of the Versatile Link Transceiver (VTRx) with the GLIB system. The second generation of the board that is currently designed will also be able to host the dual Versatile Link transmitter (VTTx). This functionality is very important since it allows the evaluation of Versatile Link components in the laboratory and more generally of GBT-based systems by integrating them in an FPGA-based environment as the GLIB. A third system which is under development is an AMC PCI Express (PCIe) adapter card. This card targets to provide a high bandwidth interconnection between a PC and a GLIB AMC used on a bench by implementing a quad-lane PCIe 2.0 link over cable. Finally, it is worth mentioning that several commercial add-in boards are already part of the GLIB ecosystem and have been used extensively e.g. an FMC with 4 SFP+ sockets. This article presents the status of the envisaged GLIB ecosystem which will offer a complete solution for beam or irradiation tests of detector modules as well as for the evaluation of optical links in the laboratory, including a Graphical Users Interface (GUI) to ease its access and control.
