Xilinx UG198 Virtex-5 FPGA RocketIO GTX Transceiver, User Guide

Chapter 1Introduction to the RocketIO GTXTransceiverOverviewThe RocketIO GTX transceiver is a power-efficient transceiver for Virtex®-5 FPGAs. TheGTX transceiver is highly configurable and tightly integrated with the programmable logicresources of the FPGA. It provides the following features to support a wide variety ofapplications:• Current Mode Logic (CML) serial drivers/buffers with configurable termination,voltage swing, and coupling.• Programmable TX pre-emphasis, RX equalization, and linear and decision feedbackequalization (DFE) for optimized signal integrity.• Line rates from 750 Mb/s to 6.5 Gb/s, with optional 5x digital oversampling requiredfor rates between 150 Mb/s and 750 Mb/s. The nominal operation range of the sharedPMA PLL is from 1.5 GHz to 3.25 GHz. These are nominal values, see DS202: Virtex-5FPGA Data Sheet for specifications.• Optional built-in PCS features, such as 8B/10B encoding, comma alignment, channelbonding, and clock correction.• Fixed latency modes for minimized, deterministic datapath latency.• Beacon signaling for PCI Express® designs and Out-of-Band signaling includingCOM signal support for SATA designs.• RX/TX Gearbox provides header insertion and extraction support for 64B/66B and64B/67B (Interlaken) protocols.• Receiver eye scan:♦Vertical eye scan in the voltage domain for testing purposes♦ Horizontal eye scan in the time domain for testing purposesThe first-time user is recommended to read High-Speed Serial I/O Made Simple [Ref 1], whichdiscusses high-speed serial transceiver technology and its applications.Table 1-1 lists some of the standard protocols designers can implement using the GTXtransceiver. The Xilinx® CORE Generator tool includes a Wizard to automaticallyconfigure GTX transceivers to support one of these protocols or perform customconfiguration (see Chapter 2, “RocketIO GTX Transceiver Wizard”).The GTX_DUAL tile offers a data rate range and features that allow physical layer supportfor various protocols as illustrated in Table 1-1.RocketIO GTX Transceiver User Guide www.xilinx.com 23UG198 (v3.0) October 30, 2009