Minutes of Weekly Meeting, 2011-07-11

Call to Order: 11:05 EDT

1. Roll Call

Patrick Au
Ian McIntosh

Roll Call:
Heiko Ehrenberg
Eric Cormack
Peter Horwood
Carl Walker
Adam Ley
Brian Erickson
Tim Pender (joined 11:11am EDT)
Brad Van Treuren (joined 11:33am EDT)

2. Review and approve previous minutes:

Approval of June 27 minutes (draft sent 27 June):

  • Corrections:
    • Delete "{Harrison joined}" (end of old actions)
  • Mover: Eric
  • Second: Brad
  • Approved?: yes, no objections

3. Review old action items

  • Adam proposed we cover the following at the next meeting:
    • Establish consensus on goals and constraints
    • What are we trying to achieve?
    • What restrictions are we faced with?
  • 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
  • Ian/Brad: Condense gateway comments and queries into a concise set of questions. - Ongoing
  • All: Forward text file to Ian containing keywords from review of meeting minutes. - Ongoing.
  • Carl/Brad: Get annotated keyword worksheets to Ian by Wednesday Close of Business. - Ongoing
  • All: Consider how a keyword can be used to define the chain configuration for a given test step, and what that keyword might be.
  • Ian: Circulate Whiteboard diagram from today's meeting to the group. DONE

4. Discussion Topics

  1. Explore communication between a pair of devices
    - Avoid the problems of hierarchy for now
    - Continue simple diagram development
    • [Peter] didn't we specify the communication at the last meeting when we said 'IEEE 1149.1'
    • [Tim] what if those devices are not 1149.1 compliant, such as a linker;
    • [Heiko] well, I guess we are supposed to ignore any hierarchy problems;
    • [Heiko] things we may want to discuss include scan chain (daisy chain?) connections, ambiguity when scan chains breaks (e.g. when scan chain breaks between IC1 and IC2, is TCK or TMS or TDO on IC1 bad or is TDI on IC2 bad?);
    • [Tim] signal quality becomes important, especially on TCK;
    • [Heiko] max TCK of the two devices; TAP voltage level;
    • [Tim] TRST* signals on multiple devices, when bussed together (are all devices use an internal pull-up resistor, or do some have a pull-down resistor?);
    • [Tim] we need to consider a master/controlling device when we talk about 'communication', someone needs to drive the test pattern, communicating with the devices in the scan chain;
    • [Heiko] what about multiple scan chains?
    • [Tim] pretty much the same things apply as for single scan chains; you could draw a box around a device and say 'this is a device' or 'this is a scan chain' and have the same requirements as far as communication is concerned;
    • {Brad joined at 11:33am EDT}
    • {Heiko summarized the discussion so far for Brad}
    • [Brad] what about compliance enable pins?
    • [Heiko] good point, we haven't talked about those yet;
    • [Brad] the discussions we are having now are about the relationships of / interoperability between multiple devices;
    • [Brad] should we make it a SJTAG requirement that compliance enable pins can be set in an automated way?
    • [Heiko] I think I'd be in favor for that; if compliance enable pins are set by manually setting jumpers then we may be missing some use cases (you may not want to have to disassemble the system in order to change jumper switch settings on a board for compliance conditions)
    • [Brad] for now we could leave it at 'we need to be careful with chain management, especially for compliance enable conditions'
    • [Tim] we need to be careful to not reset a part of the circuitry which then takes the system out of compliance enabled mode
    • [Brad] last week we talked about 'overshooting', this would make some of the primitives (scan segments) we talked about become obsolete; the vector doesn't match exactly the target (scan segment) anymore, there are extra bits that are shifted;
    • [Heiko] do we want to continue discussion on this next week or should we move on to a different topic?
    • [Brad] perhaps we can move on to some other type of relationship between devices, e.g connectivity test

5. Key Takeaway for today's meeting

  • we need to be careful with scan chain management
  • overshifting requires rethinking of the scan segments model

6. Schedule next meeting

Next Meeting:
- July 18
- July 25

7. Any other business

  1. ITC - Advance Program now available - SJTAG not expressly mentioned in Posters
    Trying to schedule time for Fringe Meeting. The "default" slot on Thursday isn't convenient for Ian - trying to get Wednesday PM.

8. Review new action items


9. Adjourn

12 noon EDT