Minutes of IEEE P1800 SV-AC meeting #2010-06
Written by: Dmitry Korchemny
Date: 2010-06-01
Time: 16:00 UTC (9:00 PDT)
Dial-in information:
Meeting ID: 38198
Phone Number(s):
1-888-813-5316 Toll Free within North America
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 2010-04-13:
v[xxxxxx] Laurence Bisht (Intel)
v[xxxxxx] Eduard Cerny (Synopsys)
v[x-xxxx] Ben Cohen
v[x-xx-x] Surrendra Dudani (Synopsys)
v[-xxxxx] Dana Fisman (Synopsys)
v[-xxxxx] John Havlicek (Freescale)
v[xxxxxx] Tapan Kapoor (Cadence)
t[xxxxxx] Dmitry Korchemny (Intel – Chair)
v[xxxxx.] Scott Little (Freescale)
v[xxxxxx] Manisha Kulshrestha (Mentor Graphics)
v[xxxx..] Anupam Prabhakar (Mentor Graphics)
v[xx-xxx] Erik Seligman (Intel)
v[-xxxxx] Tom Thatcher (Sun Microsystems – Co-Chair)
|- attendance on 2010-06-01
|--- voting eligibility on 2010-06-01
Agenda:
- Reminder of IEEE patent policy.
See:
http://standards.ieee.org/board/pat/pat-slideset.ppt
- Minutes approval
Surrendra: Move to approve the minutes from 2010-05-25.
Second: Ben
The motion passed: 0n/0a/9y.
- Issue prioritization
- Issue resolution/discussion
2804: Need to clarify rule (b) in 16.15.6 to allow inferred clock when expression appears in procedural assertion
Surrendra: Need to address inference of clocking block events also.
Erik: Addressing clock usage in checkers, tasks and clocking blocks may impose a heavy burden on compilers/simulators, and be problematic for separate compilation.
Dmitry: The case of separate compilation is not symmetric: checkers cannot be compiled without knowing their instantiation context, but modules can be compiled without having access to the source file of a checker they instantiate.
Ed: The event in a clocking block is triggered in the Observed region. Usually should not be an issue, but a problem may arise when an assertion uses a sequences and they both use an event from a clocking block, one as a clocking event, and the other directly.
Erik: Will need to submit a Mantis item
Ed: Should be a problem to analyze a clocking block for inference in the general case.
Manisha: Eliminate rule about posedge/... clock for clocking block events.
Ed: Events from clocking blocks are rarely used in always procedures. We may infer them in any case.
Discussion summary:
- If a clock is passed to a task called in an always procedure does not prevent clock inference in concurrent assertions instantiated in this procedure.
- The clock in an always procedure inside a checker will be inferred according to the checker instantiation context, as shown in the following example:
checker check(a, event clk);
always
@clk
a1: assert property(a);
endchecker
module m(logic clock, x, y, ...);
check c1(x, clock); // check compilation error: no clock inferred for a1
check c2(x, posedge clock); // OK
endmodule
- If an event generated in a clocking block controls an always procedure then it will be inferred in assertions instantiated in thie procedure.
2955: Checker example is wrong
No proposal is ready yet.
Ben: Should we discuss parameters in checkers in the context of this example?
Dmitry: This enhancement request is in our top priority issues and we will be able to discuss it when the PAR id approved.
3113: Add port_identifier to constant_primary BNF for sequences, properties and checkers
Laurence: LRM explicitly specifies that this usage is legal in 16.8, 16.13, and 17.2. However, this is not reflected in BNF. BNF should allow this explicitly.
Ed: But the BNF should treat sequences and properties in the context of their instantiation.
Dmitry: Need to check this.
Dmitry: Instead of fixing the BNF (and this will require massive changes in the BNF) we could just add a note to Annex A that the BNF should be treated appropriately (according to the rewriting algorithm).
2732: Clarify timing diagram in Figure 16-4?Future value change
Dmitry, Scott: Postpone this issue until John is back
1933: 16.13.6 reference to triggered method can be improved
Ed: In the LRM 2009 the reference is correct.
Move: Ed: resolve 2009 as "No change required"
Second: Manisha
Motion passed: 9y/0a/0n
2387: Layout of 16.11 is inconsistent
Move: Ed: accept the proposal
Second: Erik
Motion passed: 9y/0a/0n
2291: the description of $assertoff blurs assertions and attempts
Ben, Erik: The proposal is correct.
2330: Clarify that number_of_ticks argument to $past must be compile-time constant
Dmitry: Need to fix the reference.
2362: 16.14 mention of assertion control system tasks is unconnected
The clause numeration in the proposal is out of date. Need to find the exact place.
The following issues have not been covered:
2825: 16.16 Disable iff: checkers not included in list of default extensions
2754: P1800-2009 : Can clock change in conditional branch of 'if' operator
2927: Precedence between sequence/property operator and normal expression operator
2452: No vacuity information about synchronous aborts
2557: Rules for passing automatic variables to sequence subroutines are not clear
- Opens
Actions:
Erik - update proposal for 2804
Laurence - prepare proposal for 3113
Ben - Create a PDF proposal for 2291
Dmitry - Fix 2330
Scott - Fix 2362