Minutes from SV-AV Committee Meeting
Date: 2010-09-14
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:
- Reminder of IEEE patent policy.
See:
http://standards.ieee.org/board/pat/pat-slideset.ppt
- Minutes approval
-
F2F meeting (discussion)
- Email ballot results
2452: No vacuity information about synchronous aborts
- New issues
3206: Deferred assertions are sensitive to glitches
- Requesting authorization to work on additional enhancements
- Enhancement progress update
2476: Need clarification about system functions $onehot, etc
Checker usability enhancements
- Issue resolution/discussion
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[-xxxxx--xxx] Laurence Bisht (Intel)
v[xxxxxxxxxx-] Eduard Cerny (Synopsys)
v[xxxx-xxxxxx] Ben Cohen
v[-x--xxxxxxx] Surrendra Dudani (Synopsys)
n[xx---x-xxxx] Dana Fisman (Synopsys)
v[-x-xxxxxxxx] John Havlicek (Freescale)
v[xxxxxxxxxxx] Tapan Kapoor (Cadence)
t[xxxxxxxxxxx] Dmitry Korchemny (Intel ¿ Chair)
v[xx-xxxxxxxx] Scott Little (Freescale)
v[xxx-xxxxxxx] Manisha Kulshrestha (Mentor Graphics)
v[xxxxxxxxxxx] Anupam Prabhakar (Mentor Graphics)
v[xxxxxxx-xxx] Erik Seligman (Intel)
v[xx-xxxxxxx.] Samik Sengupta (Synopsys)
v[xxxxxxx-xxx] Tom Thatcher (Oracle ¿ Co-Chair)
|- attendance on 2010-09-14
|--- voting eligibility on 2010-09-14
Minutes:
- Reminder of IEEE patent policy.
See:
http://standards.ieee.org/board/pat/pat-slideset.ppt
Participants were reminded of the policy.
- Minutes approval
Erik: Move to approve minutes
Scott: Second
Vote results: 11y, 0n, 0a
- Email ballot results
2452: No vacuity information about synchronous aborts
Dmitry: 2452 passed with 11y, 0n, 0a
Note: added text should be in blue.
Dana will update proposal to make new text blue, and Dmitry will
update status.
Dmitry: Even though the proposal passed, there were some questions raised
about it.
- New issues
3206: Deferred assertions are sensitive to glitches
Dmitry: If a deferred assertion references both a design variable and
a test bench variable, then there could be false firing.
Tom: So you are saying that the deferred assertion will give its result
in the Reactive region, but reactive region events could cause another
pass through the active/NBA regions, resulting in a second
evaluation being reported in the same time step.
Tom: Don't see how you are going to fix this. How would you know
that any pass through the Reactive region is going to be the
last for that time step?
Dmitry: A very serious problem?
Ed: Could you use a concurrent assertion instead if you are concerned
about this?
Dmitry: Concurrent assertions are less friendly.
Tapan: What is typical use model where a deferred assertion references both
test bench variables and design variables?
Dmitry: Imagine you are replacing part of design with a behavioral model
written in SVTB. Now deferred assertions may reference both
design and test bench variables.
Tapan: Is this a standard usage described in UVM?
Dmitry: Will add an example to the Mantis item.
- Requesting authorization to work on additional enhancements
Dmitry: Would like to request working group to work on the following
enhancements: 3206 3191
3206: Deferred assertions sensitive to glitches
3191: Allow sequence methods with sequence expressions
Ben: What about 3195? "Local variable flow-in"
Dmitry: If we have permission, then we can work on several enhancements in
parallel.
-
F2F meeting (discussion)
Dmitry: Would like to have face-to-face meeting in November.
Suggest Silicon Vally location.
Ben: Won't be able to attend.
Scott: Doubt that company will pay for travel. Can attend by phone.
Second week of November not good.
Dmitry: Goal is to discuss more enhancements.
Erik: Suggest sending out an e-mail poll.
- Enhancement progress update
2476: Need clarification about system functions $onehot, et
Dana: What about sub-dividing the functions in the BNF according to type
that they return
Erik: Didn't see the need. These BNF productions are not in Annex A.
Dana: Purpose of BNF is to show how things are used. Things that return
different types may only be used in the context where that type makes
sense.
Erik Is that the case? production "expression" could take on many types.
Erik Will look into modifying BNF.
Dmitry: Should I appoint reviewers, or just vote?
Manisha: In the BNF, the names of all the functions should be in red.
Dmitry: All terminals should be in red. Also parenthesis should be in red.
Erik: Will fix that.
Dmitry: When updated proposal is ready, will call for vote.
Erik: Should we get sv-bc feedback before vote?
Dmitry: We'll vote on it first, then send to sv-bc
Checker usability enhancements.
Dmitry: Went through the checker usability document, explaining the differnt
sections.
Dmitry: The semantics of the $sampled function are re-defined for rand
checker variables.
Erik: Are you shifting the meaning of sampling?
Erik: Why does the text say the value from the postponed region.
Dmitry: Regular variable : sampled value is same throughout time step
Randomly assigned variable $sampled changes at observed region
Tom: But you shouldn't be referencing rand checker variable outside a
checker. The checker code all executes in Reactive region.
However, if XMRs are allowed to rand checker variables, then you will
have a big mess.
Dmitry: Other enhancements in document: add always_ff and always_comb
Dmitry: Continuous assignments:
Tom: Should not have cont assign that could update in two different regions
Cont assigns should always update in Reactive region. Even though
a checker argument updates in Active, the continuous assignment inside
the checker should always update in the Reactive region.
Manisha: What is the Re-Inactive region
Tom: No assignments are allowed in the Re-Inactive region. A continuous
assignment should never update there.
Dmitry: Checker output arguments
Connection to checker output argument should imply a continuous
assignment.
Tom: One more comment: We have talked about how the current checker
sampling breaks the rewriting algorithm. We should explain in this
document what the rewriting algorithm is, why it's important, and
how it is broken now.
Dmitry: Will try to put that into the document.
Meeting Adjourned.