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Minutes from SV-AC Committee Meeting

Date: 2010-09-21

Time: 16:00 UTC (9:00 PDT)

Duration: 1.5 hours

Dial-in information:

--------------------

Meeting ID:            38198

Phone Number(s):

1-888-813-5316         Toll Free within North America

Agenda:

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- Reminder of IEEE patent policy.

See: http://standards.ieee.org/board/pat/pat-slideset.ppt

- Minutes approval

- F2F meeting (discussion)

- Email ballot results

2476: Need clarification about system functions $onehot, etc

Passed: 13y/0n/0a

- New issues

- Enhancement progress update

Checker usability enhancements

- Issue resolution/discussion

3008: In $past BNF, "expression" should be "expression1"

1853: BNF for calls to $rose and other sample value system functions.

2904: Clarify when disable iff condition must occur relative to starting

and ending of an attempt

3134: sequence and property range parameters are erroneously defined

3135: Verbal explanation of nexttime and always is misleading for

multiple clocks

1678: Clarify that rewriting algorithm doesn't replace name resolution

2571: confusing assertion clock inference rule

2386: Rename 16.9 to "Local variables"?

3117: make it clear that rewriting algorithm (F.4.1) applies to checker

and let

- Opens

Attendance Record:

------------------

         Legend:

                 x = attended

                 - = missed

                 r = represented

                 . = not yet a member

                 v = valid voter (2 out of last 3 or 3/4 overall)

                 n = not a valid voter

                 t = chair eligible to vote only to make or break a tie

Attendance re-initialized on 2010-07-06:

  v[x-xxxxx--xxx] Laurence Bisht (Intel)

  v[xxxxxxxxxxx-] Eduard Cerny (Synopsys)

  v[xxxxx-xxxxxx] Ben Cohen

  v[x-x--xxxxxxx] Surrendra Dudani (Synopsys)

  v[xxx---x-xxxx] Dana Fisman (Synopsys)

  v[x-x-xxxxxxxx] John Havlicek (Freescale)

  v[xxxxxxxxxxxx] Tapan Kapoor (Cadence)

  t[xxxxxxxxxxxx] Dmitry Korchemny (Intel ¿ Chair)

  v[xxx-xxxxxxxx] Scott Little (Freescale)

  v[xxxx-xxxxxxx] Manisha Kulshrestha (Mentor Graphics)

  v[xxxxxxxxxxxx] Anupam Prabhakar (Mentor Graphics)

  v[-xxxxxxx-xxx] Erik Seligman (Intel)

  v[xxx-xxxxxxx.] Samik Sengupta (Synopsys)

  v[xxxxxxxx-xxx] Tom Thatcher (Oracle ¿ Co-Chair)

    |- attendance on 2010-09-21

  |--- voting eligibility on 2010-09-21

Minutes:

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- Reminder of IEEE patent policy.

See: http://standards.ieee.org/board/pat/pat-slideset.ppt

Participants were reminded of the policy.

- Minutes approval

Scott: Move to approve minutes

Tapan: Second

     Vote results: 12y, 0n, 0a

- F2F meeting (discussion)

    Silicon Valley: Tom, Anupam, Erik, Dmitry

    Ed, Surrendra:  Suggested Boston

Dmitry: Would it help to move to coincide with DV-CON? (Feb 28--Mar 3)

Ed: May help, but can't know in advance. Would also have more things

     to discuss at this time.

Tom: Agree that we would have more to discuss in DV-con time frame.

Dmitry:    Also, Nov date would coincide with IC_CAD as well.

Dmitry:    Will conduct one more poll on the time-frame, Decide next time.

- Email ballot results

2476: Need clarification about system functions $onehot, etc

Passed: 13y/0n/0a

Dmitry: Has implemented two friendly amendments.

Dmitry: This proposal takes care of 3008 as well.

- Issue resolution/discussion

3008

Scott:     Move to close 3008 as resolved by 2476.

Tom: Second

Vote Results:    12y, 0n, 0a

- Enhancements progress update

Checker usability

Dmitry: Discuss definition of sampling.

Dmitry:    Current proposal: "Sampled" defined differently for different data:

     Example: checker rand variables, $sampled returns value assigned

           at beginning of Observed

           Automatic variables: $sampled(x) = x

Manisha: Definition seems fine: just confused about automatic variables.

     They have short life span. They may not exist at end of simualtion

     tick

Dmitry:    Then it may be illegal to call $past on an automatic.

     May also be hard to define $past for local variables.

Dmitry:    Continuous assignments and always_comb/blocking assignments.

Tom: Make things consistent. Continuous assignments in checkers always

     update in the Reactive region. Even if a checker input changes in the

     active region, the assignment would be scheduled for the Reactive

     region.

John: Will have to think about examples of interacting agents.

Manisha: Are you sure that design continuous assignments always update in

     the Active region?

Dmitry:    Pg 31 of standard: 4.9.1

     We can ask other committees to be sure.

John: Will try to think of examples.

Dmitry: Who would like to work on proposal?

Anupam: 3034, currently assigned to me.

Manisha: Can volunteer to help.

Checker outputs

Lawrence: BNF of checker outputs. Need to specify input/output of each

port.

     To maintain backward compatibility, if direction not specified, first

     port would be considered an input.

Dmitry:    But it would be inconsistent with everything else?

Ben: Can't it be like a module?

Lawrence: In modules, you need to specify direction.

Ben: But some people like to put outputs first in the port list.

Dmitry:    You can do it, you just need to specify "output" for the direction

     of the first port.

Lawrence: Do we want to allow untyped outputs for checker?

Dmitry:    Why not?

Scott:     For modules: the LRM says if the direction is unspecified, the port

     type defaults to inout. this proposal is inconsistent with this.

Dmitry:    We are not intending to introduce inout ports for checkers right

now.

Manisha: Would prefer to default to input. inout ports cause more overhead.

Anupam:    So we plan to make input the default direction, and we are not

     proposing inout ports.

Ben: Dmitry was talking about using a checker as a model. For this

     application, It may need tri-state ports, inout ports, etc.

- Issue resolution/discussion

2904

Anupam:    Simulation should not need to retract something that has already

     been evaluated. Proposed to change the line Dana had modified.

Anupam: In a single-clocked case, should be consistent. In multi-clocked

     case there would be a race, but don't want to deal with that.

     Proposed change is in e-mail

Dmitry:    Should you mention Observed region?

Anupam:    Sentence mentions assertion evaluation. This occurs in Observed

     region. Shouldn't be necessary to explicity mention Observed

     region.

John: You are not specifying an ordering between disable iff condition and

     the assertion evaluation?

Anupam:    Correct. No ordering is implied.

Meeting adjourned.

- Enhancement progress update

Checker usability enhancements

-- Main.ErikSeligman - 2010-10-01
Topic revision: r1 - 2010-10-01 - 20:20:50 - ErikSeligman
P1800