In recent years, the sheer number of advanced digital networks on circuit boards has grown exponentially. These chip-to-chip interconnects, which are largely comprised of AC-coupled and/or differential networks, are much more difficult to test than the DC-coupled and single-ended nets they have replaced.
The solution is an extension to the IEEE 1149.1 boundary scan (JTAG) standard called IEEE 1149.6 for Boundary-Scan Testing of Advanced Digital Networks. It specifies supplemental boundary-scan cells on high-speed networks and corresponding boundary scan instructions that are capable of generating stimuli and capturing responses for AC coupling and/or differential signaling.
Download the 1149.6 Tutorial by Adam Ley, our chief technologist and a member of the IEEE 1149.6 working group the developed this new standard, to learn more about its background, architecture and instructions.