Exploring and Comparing IEEE P1687.1 and IEEE 1687 Modeling of Non-TAP Interfaces

The industry is moving forward with non-TAP, chip-level interfaces driving IEEE 1687-2014 networks. Recent literature not only describes such interfaces, like I²C and IEEE 1149.7 variants, but also demonstrates that such interfaces to IEEE 1687 are already proven in silicon. Common to those implementations is the need for "private" extensions of IEEE 1687 to make it support non-TAP interfaces. The goal of IEEE P1687.1 is to directly support non-TAP interfaces. In this work, we summarize the thought progression from IEEE 1687's data register callbacks to IEEE P1687.1's transfer function, which allows alignment with IEEE P2654, and possibly IEEE P1687.2.