Bus testing in a modern era

The application of IEEE Std. 1641 to Bus testing has been (and continues to be) a major hurdle to its full adoption on deployed ATE systems. The IEEE Std 1641-2010 standard had several new primitives added for support of both Digital and Bus testing. These digital changes [8] focused primarily on the digital aspects usage, and although it added BSCs to support bus communication and protocols, the report did not provide detailed and definitive examples. There is now a growing requirement to create a set of use cases and recommended practices to support the bus testing domain in 1641, for typical UUT buses, e.g. RS232, 1553, TCP/IP protocols including HTTP, CAN Buses, J1939. The paper considers the commonly used bus implementations and describes how to best model buses from their physical layer through to their message or application layer and associated protocols. The paper identifies the relative merits of different methods of bus testing and provides guidance on the level required and shortcuts that can practically be taken when using standard bus domains. This will be examined through a series of examples and consider both using buses to communicate messages/data to a UUT and how `error testing' can be performed to test that the UUT is correctly behaving when a bus message or protocol is corrupt or out of specification. The paper aims to identify if the existing IEEE 1641 and ATML test standards have the depth and required flexibility to meet the full range of bus testing requirements of our modern systems.