Languages to Support Boundary-Scan Test

Abstract

ion From Detail Traditionally, test data interchange has occurred at a very low level -involving detailed binary data and signal timings. Where boundary-scan is extensively used, interchange can occur at an abstracted level -provided that the target test system can comprehend the transmitted data. For example, where all testing is to be achieved through the 1149.1 interface, interchange may be at the level of instructions and associated data values, with the method of application being implied from a statement that the circuit complies with the standard. A key advantage of boundary-scan-based testing is that test data can be used both in the factory and later in life -for example, during field fault diagnosis or in depot repair. Whereas a test system designed for use in a factory environment may offer high-throughput, support for fault diagnosis, and other 'top-end features, testers intended for field use may be based on off-the-shelf notebook PCs, possibly with plug-in modules that support boundary-scan test access. This latter type of 'tester' may be limited to low-throughput go-nogo testing. The objective for future test data interchange standards should be to allow the same basic test programme to be used both in the factory and in the field To use an analogy with microprocessor software, test data interchange is moving from 'microcode' to 'assembler'.