A flexible software framework with dynamic expansible signals

IEEE Std 1641 defines a method of accurately defining signals as used in test procedures and requirements. It defines many common signals in the basic signal component (BSC) and test signal framework (TSF) layers. New signals can be described by combining existing signals, and there is no limit on the expansibility of signals. However, user-defined signals are not convenient to use by the support of the standard. The standard gives each signal a different interface description language (IDL) definition, including its methods and attributes. The signal definitions are fixed in the test program language (TPL) layer. It is capable of performing a compile-time and runtime checking (e.g. a consistency check between signals, attributes and values) on existing signals defined in the standard. Although user-defined signals can be imported into the TSF library, it is difficult to give them a same compile-time and runtime support by the given software framework. To solve this problem, we propose a flexible software framework, which can simply expand new signals and delivers an undifferentiated compile-time and runtime support to user-defined signals. In our proposed framework, we define common interfaces which do not depend on signals. All signals are described in an expansible signal library. The resource manager dynamically manipulates signals based on the signal library, and performs a runtime support. The TPL compiler dynamically identifies signal names and attribute names with a finite state machine, and performs a comprehensive compile-time check based on the signal library. In the framework, new signals can be easily added into the library and have a same situation as existing signals. The above proposed software framework is implemented in LabWindows/CVI. Using experiences show that the proposed framework has a strong signal expansibility, which simplifies the process of expanding new signals, and makes the system simpler and more efficient.