Minutes of Weekly Meeting, 2017-05-22

Meeting called to order: 11:17 AM EDT

1. Roll Call

Ian McIntosh
Carl Walker
Brian Erickson
Heiko Ehrenberg
Brad Van Treuren
Eric Cormack (joined 11:19)

By Proxy:

Bill Eklow
Peter Horwood

2. Review and approve previous minutes:

  • Approval of May 15 minutes (draft circulated on 05/15/2017)
    • Brian moved to approve, seconded by Brad. 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 (http://files.sjtag.org/Ericsson-Nov2006/STAPL-Ideas.pdf)
  • Ian: Add the previously discussed lists to the 'master' template. Ongoing.
    • Some sections need further expansion that may take time to develop.
  • Brad: Send diagrams and DSL to Jeff Rearick and Martin Keim for comment. COMPLETE

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
  • Possible invitation for Al Crouch to talk about Parallel SIBs.
  • Python Netlists (SKIDL) suggested by Brad for discussion.

5. Discussion Topics

a. Building Blocks - Use Case of a simple Interconnect Test - Continued, Implications for tooling.

  • Responses had been received from both Jeff Rearick and (in brief) from Adam.  Ian summarised both as confirming that the extra iApply was indeed required between the iWrite and iRead statements to get the intended operation and ensure portability.  Ian also inferred that the replies indicated that the retargetter wasn't expected to do as much resolving as we had perhaps initially assumed.  Brad agreed that 1687 had a simpler view, driven mainly by focus on (chip) ATE platforms, which is different from the multi-device case on board tests. 
  • For these ATEs the retargetter can generate STIL or similar that can run on the ATE platform, and there's no application for dynamic behaviour based on feedback from other instruments. Brad added that it wasn't the objective of the standard to focus on the single chip case, but was largely the perspective of those implementing the retargetters.
  • Brad was unsure about any vendors currently providing 1149.1-2013 support, as it all seemed to be done manually so far.  Ian commented that may be due to a lack of demand until devices that use the extensions are actually in the mainstream market. Brad agreed. 5 years had previously been suggested as typical for adoption to settle in.
  • Considering the PDL example, Ian noted that, as written, it required to shift twice as many bits as the "pure" 1149.1 example.  Brad commented that where e.g. a 1687 hierarchy exists, the order of reads and writes when iApply is executed may be determined as result of what is necessary to set up the AccessLink (SIBs); there's a question of at what point is the model updated?  Ian thought this must be a shortfall in the standard although Brad noted that there may be something in the ICL to define that behaviour. Ian acknowledged that he often forgot about ICL.  Brad wasn't convinced that there was a solution in 1149.1-2013 to state that behaviour.
  • Brad commented that when he and Michele were working on NSDL, there was always a read, but with a conditional if a write was required before the read. This was the kind of decision the retargetter needs to make based on the ICL.
  • Brad reported that a benefit to 1687.1 out of our discussion was a realisation that the retargetter needs to be able to deal with more than just a single device.
  • {Brad shared the DSL code samples updated during the previous meeting}
  • Ian observed that if each iWrite/iApply and iRead/iApply group were treated as a single statement, then it would look more like the I2C and SPI examples. Brad described this as PDL procedures and started to define PDLWrite and PDLRead procedures, then re-wrote the example to use these calls.
  • Brad noted that we now had, in each of the interface examples, addressing (effectively the AccessLink setup) along with data in each of the commands. So not just a path to the pins but the network was selected in the PDL (could be parts of the same shared network). We have not just the instruction but also the offsets in the chain.
  • Brad suggested a key takeaway from this was that each command has an explicit or implicit AccessLink specification along with the data to be applied to that register.
  • It now looked plausible that we could derive a generic/abstract form for these tests. The data is the same except for any padding required by the interface.  Syntactically, the address in each case is just an argument although semantically they are different.  Ian felt that the topic for next week initially needed to look at how the address translation could be effected - Brad added consideration of pure translation versus something in ICL.
  • The updated DSL code is here: http://files.sjtag.org/Brad/Example%20DSL%20of%20Models_20170522.txt.

6. Topic for next meeting

  • Building Blocks - Use Case of a simple Interconnect Test - continuation.
    • Translating AccessLink specification.

7. Key Takeaway for today's meeting

  • Each command has an explicit or implicit AccessLink specification along with the data to be applied to that register.

8. Glossary terms from this meeting

  • None.
  • Carried over:
    • Definition of "interchangeability" required.
    • 'Instance' (or a more specific version of the term) may require definition in future.
    • 'Master through Slave Mode'
    • 'Master to Master Mode'
    • Need a refined definition of "system" for the purposes of the PAR.
    • 'Priority' - may relate to 'frequency' and 'urgency' in distinct definitions.

9. Schedule next meeting

  • Next meeting June 5 (no meeting on May 29).
    • Heiko and possibly Eric out.
  • June schedule:
    • 12, 19, 26.

10. Any other business

  • Ian hopes Michele will be able to provide a fuller report on the TESTA tutorial in due course.

11. Review new action items

  • None.

12. Adjourn

  • Brian moved to adjourn, seconded by Eric.
  • Meeting adjourned at 12:02 PM EDT

Respectfully submitted,
Ian McIntosh