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December 2016 • SMT Magazine 83 BOUNDARY SCAN MEETS FUNCTIONAL TEST device offers excellent flexibility for compre- hensive testing of prototypes, for low to mid- range production volumes, as well as for repairs. In addition, there are also very powerful platforms for open, modular instrumentation of traditional functional testers, which can be very well configured towards structure testing with the corresponding components. One of the leading integration platforms in this respect is PXI, or PXI Express (Figure 11). The advantage of such architectures is the availability of a very high number of multi-ven- dor modules for almost all application and ser- vice areas. It is possible to implement flexible system concepts based on open software pack- ages such as LabVIEW or TestStand. The JTAG components are integrated on correspond- ing hardware/software plug-ins. There are also software solutions, which make it possible for the functional tester to have full control of the JTAG hardware and provide an interactive vec- tor interface. This transparent slave mode also makes it possible, for example, to implement cluster tests. A whole series of JTAG boundary scan controllers are available for the integration of embedded system access technologies, all in the natural PXI/PXIe format and implemented as a single slot instrument. The same principle of plug-in JTAG bound- ary scan components is also used for the com- bination with invasive testers such as ICT, FPT and MDA components. Here too, it is possible and useful to use interactive procedures to in- crease fault coverage. Summary and Conclusions The ever-decreasing test access is forcing a rethink of the test philosophy for modern de- signs. Embedded structural tests, such as JTAG boundary scan in combination with innova- tive, embedded functional test methods offer new approaches in this regard, up to and in- cluding embedded ATE. The focus is on improv- ing efficiency in test generation, while increas- ing test speed at the same time. This also makes it possible to maximize test coverage, as well as diagnostic quality. The use of external I/O mod- ules with FPGA offers additional options to eas- ily improve test quality. Mature and powerful platforms are available for the mix of various strategies. This also ap- plies to the combination with traditional, exter- nal test instruments. Users now have access to an extensive range of technical solutions. But the right decision must be made individually, based on an exact analysis of the product properties, process pa- rameters, and last but not least, of the cost con- ditions. SMT References 1. IEEE Std.1149.1-1990, Standard Test Ac- cess Port and Boundary Scan Architecture. 2. IEEE Std. 1149.6-2003, Standard for Boundary Scan Testing of Advanced Digital Net- works. Figure 10: Combination tester for the synchro- nized use of external tools and all embedded system access technologies on one platform. Figure 11: PXI/PXIe based combination tester, incl. MDA instrumentation.