Minutes of Weekly Meeting, 2013-05-20

Meeting called to order: 11:05 AM EDT

1. Roll Call

Ian McIntosh
Carl Walker
Brian Erickson
Eric Cormack (left 11:28)
Adam Ley
Harrison Miles
Tim Pender (joined 11:15)

Heiko Ehrenberg
Patrick Au
Peter Horwood
Brad Van Treuren

2. Review and approve previous minutes:


  • Brad had advised two corrections:
    • 'Brad noted that we still need to work out what it is we're trying to do.'
      (changing 'tha' to 'that')
    • 'Brad responded that with a Plug'n'Play scheme the UUT stores it's own tests so can adapt to configuration changes due to hot swap of boards in a backplane'
      (adding the text following 'configuration changes')
  • Ian also noted that in the latter, 'it's' should be 'its' and there is a missing 'it' between 'so' and 'can'.

Carl moved to approve with the above amendments, seconded by Adam. No objections or abstentions.

3. Review old action items

  • All: do we feel SJTAG is requiring a new test language to obtain the information needed for diagnostics or is STAPL/SVF sufficient? see also Gunnar's presentation, in particular the new information he'd be looking for in a test language
  • Harrison will attempt to come up with a table of use cases and their associated layer and what can be done at that layer. Ongoing.
  • Ian/All: Look for real world examples of boards that we could take through from board test to a system test implementation as a worked example case. Ongoing. Ian added that he expected this would take a little time.

4. Reminders

  • Consider Adam's three points (from the action from the first weekly meeting) and suggest what is preventing us from answering those questions:
    • Establish consensus on goals and constraints
    • What are we trying to achieve?
    • What restrictions are we faced with?
  • Forum thread for discussion: http://forums.sjtag.org/viewtopic.php?f=3&t=172

5. Discussion Topics

  1. Can we define what a 'system' is for SJTAG purposes, at least for a dot0 definition? What characteristics does a 'system' have that differentiates it from say a chip or a board?
    • {Tim joined}
    • As a follow on to comments made at the previous meeting, Ian want to find out if there was definition of what a 'system' was, or was not, as far as SJTAG was concerned. Ian thought this might be a key element in defining the scope of SJTAG. As a starter, Ian suggested that perhaps a characteristic of a system was that it was an assembly that performed some useful function in its own right.
    • Eric felt that a system was difficult to define as even stacked die modules could be considered systems. Tim didn't feel it was possible to define and that once you started to require a 'function' then it began to sound like a 'product' and while some systems may consist of several products, others may have no real function. Eric was in agreement with Tim's view.
    • The definition of System from the glossary on the SJTAG wiki was shared: "System: For the purposes of SJTAG, a system may be described as an aggregation of electronic circuit boards which together perform a function or range of functions."
    • Brian suggested that since things like board and multi-chip already have established test methods perhaps a system needs to comprise two or more 'modules', whatever we define as a module, such that both can be tested in conjunction. Ian felt that was fair but might become complicated in the case where an embedded controller was commanding the test. Harrison, however, been assuming this to be the case all along. The interesting aspect for him was how you get the test there and manage it.
    • Harrison noted that there are ways of performing SJTAG-like testing but not in any generic way, and that the value of SJTAG will be in bringing in standard methods.
    • {Eric left}
    • Ian agreed that most of the end-users in the group had probably arrived at some form of SJTAG in their own organizations. These were no doubt different, but that may in part be due to differences in market sectors and customer expectations.
    • Ian was reminded of comment of Harrison's from some time ago suggesting that a cluster of mobile computing platforms could be a system and wondered if that was still a pertinent view. Harrison felt it was, especially with the increased power available in 4G capable hand-held devices and the ability to create networks independent of the telephone network. Ian still wondered if that constituted a valid testable entity. Harrison thought it was and cited discussions on the possibility of giving JTAG access to the processor in much the same way is often available to USB. Ian wondered who would use it and how, and Harrison admitted that it probably hadn't been given much consideration yet, but there were prospects around yield improvement and added that both TI and Freescale had means to secure the JTAG port. Ian started to see that while a regular cellphone was unlikely to see any benefit from SJTAG, 'cellphone-in-a-box' applications, such as in truck or bus fleet management could be an SJTAG candidate, with a network of testable items. Harrison added that medical systems and instrumentation within hospitals, etc., were moving towards wireless networks.
    • Ian felt that these wireless networks could possibly be treated as almost equivalent to the physical backplane in the more conventional view of a system. The same dynamic aspects probably exist in both cases. However, a single cellphone, as a testable entity, is probably little different to the board test subject in the factory, were the manufacturer to make the JTAG port accessible.
    • The general conclusion seemed to be that we would have to accept a broad, loosely defined concept of a system for SJTAG, Tim commenting that the existing definition in the Glossary was probably OK.

6. Key Takeaway for today's meeting

  1. It seems unlikely that we can arrive at a more precise definition of what a 'system' is for SJTAG.

7. Schedule next meeting

Next Meeting:
No meeting on May 27, next meeting will be June 3.

June schedule:
3, 10, 17, 24

8. Any other business

Ian has not heard from Bill Eklow on BTW. Carl will attempt to contact him.

9. Review new action items


10. Adjourn

Brian moved to adjourn at 11:57 AM EDT, seconded by Carl.

Respectfully submitted,
Ian McIntosh