Accessing Embedded DfT Instruments with IEEE P1687

While the advancement in semiconductor technologies enables manufacturing of highly advanced and complex integrated circuits, there is an increasing need of embedded (on-chip) instruments for test, debug, diagnosis, configuration, monitoring, etc. A key challenge is how to access these instruments from chip terminals in a low-cost, non-intrusive, standardized, flexible and scalable manner. The well-adopted IEEE 1149.1 (Joint Test Action Group (JTAG)) standard offers low-cost, non-intrusive and standardized access but lacks flexibility and scalability, which is addressed by the on-going IEEE P1687 (Internal JTAG (IJTAG)) standardization initiative. This paper discusses the need of embedded instrumentation, the shortcomings of IEEE 1149.1 as well as features and challenges of IEEE P1687.