Xilinx XAPP713 Virtex-4 RocketIO Bit-Error Rate Tester, application ...

Software DescriptionRSystem Reset orPower upInit UARTGet XBERTInfoBatch DRPwrites to allMGTsPower down orreset MGTsMain MenuGet/DisplaySystem InfoSetup PMAClock ModeSetupChannelTest BEREdit PMASettingsDRP DumpScan OptimalPMA SettingsEnterChipScopeModeRead XBERTstatus viaGPIOSelectChannel(s)SelectChannel(s)Measuretime elapseSelectChannel(s)and MGTsRead all DRPregisters onboth MGTsSelectChannel(s)and MGTsControlXBERT logicvia GPIOClock modeselectionguideEdit PMAclocksettingsDRP Read-Modify-Write on PMA clocksettingsDRP Read-Modify-Write on PCS COMMAsettingsReset Channel(s)Select/InputconfigurationControlXBERT logicvia GPIOReset PMAReadXBERTstatus viaGPIOCalculateline rate andBERDisplay BERResultsRead/execute usercontrolsSelect aPMAsettingDRP Read-Modify-Writeon the PMAsettingInput newsettingInput aDRPaddressDRP write atthe addressSelect PMAsettings for thescan testInitialize allsettings to zerosValidate settingsDRP Read-Modify-Write onthe PMA settingReset BERTRun a short BERtestResetPMAResetCounterInjectErrorResetTimerRead XBERTStatus via GPIO,record the BERGenerate the nextsettingsDisplay optimalsettingsx713_13_101705Figure 13: Flow Diagram of Main Application CodeSome important C functions implemented in this main application code are described below.• Read-Modify-Write on the DRP (pma_attr_rmw): This function has the inputs of DRPaddress, bit offset, bit mask, target MGT number, target channel number, and the value towrite to the DRP register. It first reads the 16-bit value on the DRP register, modifies onlywww.BDTIC.com/XILINXXAPP713 (v1.1) April 18, 2007 www.xilinx.com 33