Implementing serial bus interfaces with general purpose digital instrumentation

The use of generic digital test instruments for emulating common serial bus protocols can provide benefits over dedicated bus test products, and often presents a trade-off between functionality, flexibility and cost. For example, a dedicated test instrument solution can offer more extensive test capabilities such as protocol support for controlling and analyzing traffic between a bus controller and a device under test. However, a more general-purpose solution that utilizes a digital test instrument can offer the flexibility to adapt to non-standard line rates and timing as well as supporting other digital test needs. Ultimately, the goal is to identify those instances where the clever or novel application of a general-purpose digital test tool is appropriate and provides tangible benefits. This paper presents an overview of how a general-purpose digital I/O instrument can used to support three widely used serial bus interfaces. By using a general-purpose digital I/O solution, users can potentially realize a lower cost test solution, a more compact test system footprint, multi-site test capability, a common user control interface and expandability for future requirements.