Connect - ASSET InterTech

When it comes to boundary scan, it’s true that necessity was the mother of invention. That is, a simple, low-overhead communications bus connecting chips, boards and systems was needed at the time and boundary scan was born. The boundary scan bus was first applied to the testing of dense circuit boards where physical access was quickly disappearing. Since then, the technology has grown into its adolescence, a time full of wonderful and unexpected surprises.

Because we were there at the beginning, we know that at first the IEEE 1149.1 Boundary-Scan Standard was developed to perform interconnect tests on printed circuit boards without requiring physical access to the board itself. Over the years since then, we’ve concentrated on making ScanWorks the best possible implementation of the boundary scan standard. We knew that boundary scan would blossom and it has. In fact, boundary scan now is a foundational technology for a whole host of other technologies, like IEEE 1532 in-system configuration (ISC) of programmable logic, in-system programming (ISP) of flash memory, IEEE 1149.4 analog test, processor emulation test, IEEE 1149.6 high-speed AC-coupled test and, most recently, Intel® IBIST (Interconnect Built-In Self Test).

I’d like to say that we were prescient enough to realize that the role of boundary scan would widen and gather under its wings all these other technologies. Well, we weren’t that smart because back in 1994 we didn’t know exactly how boundary scan was going to evolve, but we did have an inkling that the role of this new technology, if it were implemented properly, would expand with time and take on greater importance than we ever realized when the standard was being defined. And that’s just what’s happened.

Today the number of technologies that are riding the coattails of boundary scan is surprising to even us who have been involved since the very beginning. Three of these technologies, Intel® IBIST test, 1149.6 high-speed AC-coupled test and processor emulation test, are mentioned in this issue of Connect.

Intel IBIST technology is a test architecture that that company is integrating into its next-generation processor chips and chipsets to enable chip-to-chip interconnect testing and design validation of high-speed buses. IBIST leverages the boundary-scan IEEE 1149.1 specification as the hardware and software communication methodology for accessing and controlling the embedded on-chip IBIST capabilities. ScanWorks’ support for Intel IBIST consists of software test controllers to validate high-speed buses such as PCI Express (PCIe) and others, as well as fault diagnostic tools. ScanWorks with Intel IBIST tools is currently being used to test the first Intel chips and platforms to include the new test technology. Commercial availability of ScanWorks with IBIST tools is expected during the first quarter of 2005. (Click here for more information.)

Tools to take advantage of the capabilities of the IEEE 1149.6 Boundary-Scan Standard for Advanced Digital Networks were recently incorporated into ScanWorks. (Click here for more information.) Combining “dot-6” with ScanWorks means that both DC-coupled device networks, which are typically tested with 1149.1 boundary scan, can be tested in the same environment and at the same time as newer high-speed AC-coupled nets are being tested. Certain types of computing and communication systems already feature hundreds, if not thousands, of these high-speed serial links onboard.

In addition, the ScanWorks product family was expanded by integrating microprocessor emulation functional test capabilities. The new ScanWorks Extended JTAG Coverage combines standard boundary scan test with the emulation-based functional test technology of µMaster (pronounced microMaster) from International Test Technologies. (Click here for more information.) This gives ScanWorks the ability to reach places on a printed circuit board where 1149.1 boundary scan could not reach on its own, not only extending JTAG test coverage, but also adding functional test on the same platform.

These additions to the ScanWorks environment demonstrate just how versatile boundary scan technology can be when time and effort are invested in developing this technology properly. Some suppliers may approach boundary scan as though it were just another market segment to attack or a sidelight to their main business, but for ASSET InterTech boundary scan is our lifeblood. It is our only business.

Clearly, over the last 10 years we’ve seen that boundary scan is a very versatile and flexible technology. Not only does it perform effectively the necessary tasks for which it was invented, but the scope of its capabilities is wide enough that it has been able to incorporate and provide a basis for other related test and programming methodologies. We believe that boundary scan will continue to evolve and its role as a test communications protocol will only expand in the future. And we will continue to provide the best possible implementation of boundary scan possible so that it can fulfill its larger functions.