Automated Test System Of XDSL Aanalog Front-end Chip Based On Virtual Instrument

With high-definition video services becoming more and more popular in theinternet,people’s demand for high-bandwidthare increasingly strong.Due to a good solution tothe problem of crosstalk,the copper access network systemwhich is based on xDSL(digitalsubscriber line technology) has been able to provide considerable bandwidth of the opticalfiber access system.At this stage the copper access system is still an economic and securityaccess form.In the xDSL system,the dynamic performance of AFE(Analog Front End)chipdirectly determineswhetherit can provide high bandwidth.Therefore,the testing ofdynamic performanceof AFE chip is particularly important before the volume production.Thetraditional test methods of AFE chip rely on xDSL system,and need to reboot and load largesystem fileswhen taking multi-chip tests, and hence greatly reduce testingefficiency.Traditionaltest instruments cannot produce the test stimulus for AFE chip used inthe actual application scenario.The dynamic performance of the equipments used in the AFEchip test are generally worse than AFE chip itself, therefore it is difficult to accuratelymeasuee the dynamic performance of AFE chip.In order to solve the problem that the performance of traditional testing instruments isdifficult to meet the requirements of AFE chip test,test automation is hard to achieve, andthe test efficiency is low,this paper build a new type of automated test system of AFE chipwhich is based on virtual instrument. According to the dynamic performance parameters ofAFE chip, the hardware and software modules of the test system were designed in detail.Thehardware of the test system is mainly composed of analog signal generator andcollectormodule, digitalsignals generator and collectormodule, test system with AFE chipcommunication module,FPGA and digital signal generation and acquisition interfacemodule.Based on the designed hardware module, the software of the automated test systemwas designed by using LabVIEWcombined with Matlab and producer consumer designmode.The hardware and software modules of the test systemwere integrated on the NI PXIplatformto solve the problemsof the traditional AFE chip test and to obtain an efficient and accurate test system for AFE chip.Based on the test of VDSL2analog front-end chip which is newly developed, the testsystem is proved to be feasible.The system can quickly test AFE chipin variety of applicationscenarios and save the test results automatically,thus can greatly reduce the test time andincrease test efficiency.