Reusing and Retargeting On-Chip Instrument Access Procedures in IEEE P1687

This paper discusses the reuse and retargeting of test instruments and test patterns using the IEEE P1687 standard in an era where reuse of existing functional elements and integration of IP blocks is accelerating rapidly. It briefly discusses the deficiencies of existing 1149.1 (JTAG) and 1500 standards and demonstrates how the new standard, P1687, plugs these exposures by specifying JTAG as an off-chip to on-chip interface to the instrument access infrastructure. It provides a simple example to underscore the need for the standard and then builds on this example to show how the standard can be used for more complex situations.