Subject: Re: [sv-ec] Re: discrete time
From: Bernard Deadman (bdeadman@sdvinc.com)
Date: Wed Jan 15 2003 - 10:43:49 PST
With respect Surrendra, I think you should look at the Sugar 2.0 / PSL
semantics document - you're on the committee so you certainly have access
to it.
My understanding, as Erich Marschner confirmed on December 31st, is "...
Accellera PSL is not a strictly synchronous language.... Unlike ForSpec
and OVA, Accellera PSL supports asynchronous assertions (clocked or
otherwise) in a completely transparent fashion."
It may well be true that the inadequate, lowest-common-denominator sub-set
of ForSpec / OVA that's masquerading as an assertion language in
SystemVerilog needs clocks, but the almost standardized Sugar 2.0 / PSL
that spans both Formal Model checking and simulation-based verification
DOES NOT!!!!
Isn't it about time SystemVerilog had a REAL assertion capability? Will
users thank us a decade from now for rushing out an LRM based on arbitrary
decisions, that does not promote re-use between tools supporting two
related Accellera standards?
Regards
Bernard
At 01:22 PM 1/15/2003 -0500, dudani@us04.synopsys.com wrote:
>There has been no need to support Verilog events for assertions.
>Assertions, as currently defined, satisfy their requirements with the
>current notion clocks.
>Surrendra
>At 12:58 PM 1/14/2003 -0800, you wrote:
>> > From Surrendra.Dudani@synopsys.com Tue Jan 14 12:35:56 2003
>> >
>> > Delta cycles are not quantized, and not part of the language. You cannot
>> > refer to a delta cycle.
>>
>> > Surrendra
>>
>>What's your definition of "quantized".
>>
>>We're defining extensions to the language, no reason we can't add counting
>>deltas if it makes assertions more usable.
>>
>>Kev.
>>
>> > At 12:28 PM 1/14/2003 -0800, you wrote:
>> > > > From Surrendra.Dudani@synopsys.com Tue Jan 14 12:19:36 2003
>> > > >
>> > > > If two events occur within the same time unit, we can refer to their
>> > > > occurrence in certain order. However, there is no way to quantify
>> the time
>> > > > within a time unit. Assertions require quantified time.
>> > > > Surrendra
>> > >
>> > >You can count delta cycles within a tick if you need to. From a logical
>> > >standpoint all times are relative, there is no real need to differentiate
>> > >between a tick and a delta.
>> > >
>> > >Kev.
>><snip>
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