6 www.xilinx.com Spartan-6 FPGA GTP Transceiver Wizard v1.8UG546 (v1.8) December 14, 2010Preface: About This GuideTypographicalThe following typographical conventions are used in this document:Convention Meaning or Use ExampleCourier fontMessages, prompts, andprogram files that the systemdisplaysspeed grade: - 100Courier bold Literal commands that you enterin a syntactical statement ngdbuild design_nameHelvetica boldCommands that you select froma menu File → OpenKeyboard shortcuts Ctrl+CItalic fontVariables in a syntax statementfor which you must supplyvaluesngdbuild design_nameReferences to other manuals See the User Guide for moreinformation.Emphasis in textIf a wire is drawn so that itoverlaps the pin of a symbol, thetwo nets are not connected.Dark Shading Items that are not supported orreserved This feature is not supportedSquare brackets [ ]An optional entry or parameter.However, in bus specifications,such as bus[7:0], they arerequired.ngdbuild [option_name]design_nameBraces { } A list of items from which youmust choose one or more lowpwr ={on|off}Vertical bar | Separates items in a list ofchoices lowpwr ={on|off}Angle brackets < > User-defined variable or in codesamples Vertical ellipsis...Repetitive material that hasbeen omittedIOB #1: Name = QOUT’IOB #2: Name = CLKIN’...Horizontal ellipsis . . . Repetitive material that hasbeen omittedallow block block_name loc1loc2 ... locn;NotationsThe prefix ‘0x’ or the suffix ‘h’indicate hexadecimal notationA read of address 0x00112975returned 45524943h.An ‘_n’ means the signal isactive low usr_teof_n is active low.