|Upcoming SJTAG Green Papers
(A description of SJTAG Green Papers can be found
In the coming editions of the SJTAG Newsletter, we will be exploring some of
the problem domains exhibited by various SJTAG Use Cases which may or may not
have solutions available with existing industrial standards. The intent of
these Green Papers is to inspire collaboration and dialog between members of
this industry; also to help educate you to the unique difficulties faced
moving forward with providing support at the board and system level for
testing, programming, and debugging systems with various levels of complexity.
Paper 1: The first paper presents the contrast between two groups of Use Cases where one
domain requires the implicit definition of access while the second requires the
explicit definition of access to a target entity. It will inform you to the broad
behavioral requirements on what was presented in the last newsletter for
supporting Access Links and Data Links.
Figure 1 - SJTAG Use Cases
Paper 2: The second paper discusses the contrast between the need to support pre-generated
tests, which are able to be replicated for factory testing, versus the need to
support interactive configuration and control of an entity during Design
Verification Test, Hardware Debugging, and Software Debugging. Both aspects are
required to support the introduction of new designs and SJTAG needs to be able to
support both domains.
Paper 3: The third paper uncovers how the JTAG based processor debug technology is really
a specialized case of an embedded instrument that can be supported at not only the
board level, but also at the system level. There are some unique aspects to this
instrumentation that provide keen insight into the problem domain of JTAG Bridges
to other protocols controlling instruments in devices.
Paper 4: The fourth and final paper in this series explains how a special class of
instrument implementations used inside FPGA devices present problems for current
standards targeting this problem domain. These special instruments leverage
Intellectual Property provided by the FPGA vendor, which leverages the internal
processor bus yielding an indirect access to the back end instrument from the
JTAG interface. Thus, the description of the instrument behavior is masked by
the generic JTAG interface instrumentation to the internal processor bus.
Figure 2 - MBIST Ecosystem
We hope you will find this series of Green Papers to be useful in your
understanding of this fascinating problem domain of SJTAG.
From the Chair
In our last newsletter I mentioned the 2013 Board Test Workshop in Austin and I'm
going to mention it again! BTW 2014 is back as an IEEE sanctioned event and will again be held in Austin, a
little earlier than last year: September 9-11.
Unfortunately, I won't be able to make the trip this time but others from the SJTAG team will be present and
we may have something to present, based on the samplers you see in the main item in this newsletter.
BTW '14 Website: http://btw.tttc-events.org/BTW14/
As you can see, we will be releasing a series of Green Papers discussing
aspects of the SJTAG problem domain.
As we believe these will be thought provoking, and perhaps even
controversial, we want allow some time for debate between each paper so publication will be roughly
coincidental with these newsletters: We'll present an outline summary in the newsletter and the full
article on the SJTAG website.
SJTAG Website: http://www.sjtag.org/
There are several newsfeeds available on the SJTAG website. On the main site,
you can obtain feeds from:
The forums offer a range of feeds at the overall board, forum or individual discussion thread level to
suit your preferences, while our wiki supplies a feed from the
Recent Changes page.
The Q4-2014 edition of this newsletter will be published towards the end of
October 2014. Copies of past newsletters are always available on the SJTAG website.
Please use the link at the foot of the page to forward this newsletter to colleagues who may be interested in the work of
the SJTAG Group - new recipients will be offered a link to subscribe to these newsletters.