Approaches and implementation of software test and development system for embedded computer systems

Describes the conception, design and implementation of the software test and development equipment (STDE), a system which aids in the development and functional testing of software running on embedded computers in critical flight applications. The STDE was designed to perform two fundamental tasks: (1) to provide a dynamic environment for the target computer with all interfaces operational simultaneously and (2) to provide a means of building test cases and scenarios in a simple and straightforward manner with enough flexibility to accommodate future changes with little or no change to the STDE software or hardware. The hardware used to implement the system was mainly commercially available hardware: with custom hardware required only for signal combination and level conversion. The conception and development of the STDE was influenced by many factors including software testing policies, addition of support and debug software, cost and ease of implementation. The background and justification for building the STDE as well as the operational characteristics are described