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78 SMT Magazine • December 2016 ly offers several functional test options already, however, these are limited to the static level. Turning the Functional Test Environment Upside Down When the term functional test is used in production, it is nearly always first associated with the traditional version—external tester is connected to the UUT via the native connector, runs through its sequences and evaluates the re- sults. But according to table 2, there are other methods that are of interest, which are specially focused on the embedded test and have many innovative features. All these processes primarily have a single goal—to relieve the user of the need for coding their own test routines by providing preconfig- ured solutions, and to thereby ensure a much higher efficiency and predictability of the entire testing process. The actual test instruments are transferred to the inside of the UUT as part of this, and the term Embedded System Access is used. According to Figure 4, this has far-reach- ing consequences. The most obvious change is that is the trans- formation of tester parts, which started with boundary scan, has increased further and now also includes the test executor. In other words, even more use is made of the elements defined by the design. This also results in a simultane- ous reduction of external effort. The emulation test uses the native on-board processor as a test executor and by doing so, can reach all the elements connected to the core. Typically, there is also a natural partition- ing of the entire circuit through the system bus, which makes it possible to automate the gener- ation process based on models. This principle also facilitates the fast pro- gramming of flash modules. In many cases, this so-called core assisted programming offers much higher performance than boundary scan. During an emulation test, the processor is generally supplied with vectors from an exter- nal source, applies them in a natural bus cycle, reads out data and transfers them back to the parent control unit for evaluation. For this rea- son, it is only possible to carry out an at-speed BOUNDARY SCAN MEETS FUNCTIONAL TEST Table 2: Functional process for embedded text access.