Guest commentary: IJTAG, SJTAG claims premature

CJ Clark, Intellitech -- Test & Measurement World, 1/9/2007 12:26:00 PM

I listened to T&MW Chief Editor Rick Nelson’s ITC audio interview with Glenn Woppman of Asset InterTech, in which Woppman discussed IEEE P1687 (IJTAG) and a potential standard on system-level JTAG. I believe the pronouns and ownership words such as “your IJTAG,” “your SJTAG demo,” and “we have this and that” in reference to IEEE working groups (WGs) are a bit misplaced.

No company owns an IEEE standard or has anything more than two votes towards a standard, even if the company has paid consultants as the WG chairs. IEEE WGs are a collaborative effort from many companies.

Both these WGs are still in the very early stages. P1687 has yet to even agree on what the architecture to link the instruments to the TAP will even look like. Therefore, it is hard to claim something is an IJTAG demo. The principles of accessing internals for high-end test have been demonstrated by Intellitech in our FAC IP for at-speed programming of flash for some seven years now.

And SJTAG technically is not even an IEEE WG, as it does not even have a Project Authorization Request (PAR) yet from IEEE. Claiming to have demos of the standards is a bit premature. Intellitech’s shipping BERT-IP product for Serdes connections in FPGAs, which was demonstrated on customer hardware at ITC, is just as much of a demonstration of the principles of IJTAG. Our at-speed BERT for Virtex 2 and at-speed DDR memory tests were demonstrated in ITC 2005. We use an on-chip instrument that is accessed by 1149.1 for generating at-speed stimulus and receiving at-speed responses through the slow-speed standardized TAP (Test Access Port) of IEEE 1149.1 (JTAG). Similarly, Intellitech’s shipping product, SystemBIST, which was also demonstrated At ITC, has the ability to have self-test with pin-level diagnostics, the basic idea behind what may be SJTAG if it were to become a standard.

Intellitech has pioneered many of the techniques over the years and while I am very pleased to see the industry heading towards standards in these areas, I felt it necessary to emphasize that the IEEE WGs are just that--working groups--with no one company owning them or finalizing what they will be.

CJ Clark is president and CEO of Intellitech.